Blade-themed PC accessory company, Scythe, has been delivering cooling products mainly aimed at low noise and quiet performance for over 20 years. The company’s Fuma series of coolers, including the Scythe Fuma 3 we reviewed in 2023, is a community favorite. Unlike some of its competitors, Scythe is a fabless company that partners with factories in China and Taiwan for the manufacturing of its air coolers, fans, and other PC hardware.

And despite some recent troubles in Europe, the company is still prodicing new products, like the Big Shuriken 4 we’re looking at today. Despite the name, this cooler has a petite profile designed to be compatible with SFF Mini-ITX builds. The diminutive design packs six heatpipes and features the new Kaze Flex II 120AH fan to move heat away from the processor below.

Will this low-profile cooler limbo its way onto our best CPU cooler list? We’ll cover the features and benchmark results, then you can decide for yourself if it is worth purchasing.

Cooler specifications

Packing and included contents

Both Scythe’s Big Shuriken 4 and the smaller Shuriken 3 arrive in small blue and white packages, just large enough to protect and house the cooler.

The CPU cooler and fan are protected with molded foam, and the accessories are housed in a small brown box.

Included with the product are the following:

• CPU heatsink
• Kaze Flex 120 II Slim AH PWM fan
• Small tube of thermal paste
• Mounting for AMD and Intel platforms
• Installation manual

Features of Scythe Big Shuriken 4

▶️ Slim 67mm height for SFF builds

This cooler is designed for the smallest Mini-ITX SFF systems on the market, with a height of just 67mm.

▶️ Six copper heatpipes

To transfer heat from the CPU to the heatsink’s fins, the Big Shuriken 4 incorporates six standard-sized copper heatpipes.

▶️ Full RAM compatibility

The cooler does not interfere with or overhang DIMM slots. All sizes of RAM, regardless of height, are compatible with this cooler.

▶️ Kaze Flex 120 II Slim AH PWM

Scythe includes its newest 15mm (height) fan, the Kaze Flex 120 II Slim AH, with the Big Shuriken 4.

AM5 installation

1. AMD users will first have to remove the default mounting mechanism and then place the grey standoffs around the CPU.

2. Take the mounting brackets and place them on top of the standoffs, using the included screws to secure the brackets.

3. Apply thermal paste to the CPU. If you’re unsure of the best way to do this, you can follow our thermal paste application guide.

4. Press the heatsink against the mounting bars and use a screwdriver to secure it through the holes on top of the heatsink (in red below). You’ll want a thin screwdriver for this purpose, as larger ones may not fit.

5. The last step is to attach the fan’s PWM cord to the corresponding motherboard header.

Real-world testing configuration – AMD AM5 platform

My results may differ from others because I focus on outcomes that are comparable to real-world use. This means I test CPU coolers inside a closed desktop case, which increases cooling difficulty compared to other testing methods. Many test CPU coolers outside of a case on an open test bench. Open benches have lowered ambient temperatures, which in turn makes weak coolers appear stronger than they really are. Some publications have used generic thermal plates to test cooling solutions.

That being said, I am using my standardized testing setup for this review, which features a full-size case and motherboard. As with every review, your mileage may vary, as every case and its airflow are different. However, you may notice larger differences here, as I’m not testing in a Mini-ITX case.

Today’s test bench has yielded more limited results than normal, as our 9950X3D system has suffered an unfortunate failure. As such, we’ve begun testing coolers on a system with AMD’s Ryzen 9 9950X.

There are some differences in how thermal events impact the 9950X and 9950X3D CPUs. While the heat output of the CCDs in AMD’s 9950X3D is relatively balanced, the 9950X I’m using has one CCD that runs much hotter than the other, with a difference of over 10 degrees Celsius in some scenarios.

One of the purposes of today’s review is to establish how well, or poorly, a smaller SFF CPU coolers handle AMD’s Ryzen 9 9950X processor. While this review will focus on the Big Shuriken 4, we’ve tested and will also go over the results of the smaller Scythe Shuriken 3 CPU cooler.

Maximum noise levels

In terms of maximum volume, both Scythe’s Big Shuriken 4 and Shuriken 3 had relatively low noise levels, measuring 39.6 and 40.3 dBA, respectively.

PBO Performance

Enabling PBO allows AMD’s Ryzen 9 9950X to stretch its legs and guzzle power, but those legs won’t stretch very far with SFF cooling. Despite the limitations of a small heatsink, the Big Shuriken 4 is still able to handle 90% of this CPU’s default power limit in Cinebench R23.

The smaller Shuriken 3 doesn’t fare as well, dropping to 134W. But that’s kind of impressive, considering that cooler is about the size of a pack of cigarettes.

150W

For the next thermal test, I’ve set the power limit to 150W. This is about the highest power limit I would recommend for users considering the Big Shuriken 4 to keep their CPU under TJ Max, as the average temperature was measured at 79.5 degrees Celsius.

The smaller Shuriken 3 isn’t able to handle this workload, so it has been omitted from the results in this chart.

150W Noise measurements

Now, as the 150W thermal measurements demonstrated above are similar to what users might encounter in gaming scenarios, I’ve measured the noise levels of coolers in this benchmark to see how loud they get in everyday situations.

Scythe’s Big Shuriken 4 measured 39.3 dBA, a moderately low volume level.

100W thermal results

Our next test is the least-demanding benchmark featured in this review, with a workload that consumes only 100W. With this lower power limit in place, both of Scythe’s latest SFF coolers can handle the CPU with relative ease. Scythe’s Big Shuriken 4 reached a temperature of 62.7 degrees Celsius, only 5-6 degrees behind traditional single tower air coolers.

Noise-normalized testing

While the preceding results used the default fan curve of my MSI x870E Carbon motherboard, I understand many readers prefer data where cooler noise levels are equalized. For this review, two noise-normalized tests were conducted. The first test was run with Precision Boost Overdrive (PBO) active to allow for the highest possible power consumption.

Looking at this first round of results, what stands out to me is how little performance is lost when the CPU’s fans are set to 39.6 dBA and the system fans are reduced from 60% to 25% PWM.

The Big Shuriken 4 cooled 178.7W with fans set normally, but only lost 1.2W of cooling power – practically a margin of error difference when noise levels were lowered and standardized.

The other noise-normalized test we have for this review also stresses the CPU to its maximum, as above, but also adds the heat of a GPU to the mix – our MSI RTX 4070 Ti Super consumes ~295W.

Conclusion

Scythe’s Big Shuriken 4 is a worthwhile choice for builders targeting SFF systems. Its slim 67mm profile, combined with low-noise operation, delivers cooling performance superior to that of smaller SFF alternatives. It’s a compelling balance of price, performance, and size for any system where space is at a premium.

PC cooling mainstay Scythe has officially announced the shutdown of its European division due to ongoing financial difficulties. The move comes just days after the company entered provisional insolvency proceedings, leading to a restructuring of its distribution and customer support channels across the region.

In an official statement sent to Tom’s Hardware, Scythe confirmed that it will cease operations under Scythe EU GmbH effective immediately. However, the company reassured that Scythe-branded products and customer service will remain available in Europe through its network of distributors and online e-commerce platforms.

The company acknowledged that during this transitional phase, there could be some “unfinished matters,” which likely refers to potential service delays or ongoing warranty claims. Apologizing for any inconvenience to customers, Scythe also added that it will continue to uphold the principles of "responsibility and integrity," by protecting customer rights in accordance with the law.

Unlike some of its competitors, Chiba Japan-based Scythe is a fabless company that partners with factories in China and Taiwan for manufacturing of its air coolers, fans and other PC hardware. The company has been delivering cooling products aimed largely at low noise and quiet performance for more than 20 years. 

Scythe’s latest air coolers, the Mugen 6 and Mugen 6 Black Edition, are on our test bench today. The Mugen 6 features a single large heatsink with a staggered design for full RAM compatibility, paired with Scythe’s latest 120 Wonder Tornado fans. How do these models compare to last year’s Fuma 3, and are they good enough to make our list of the best CPU coolers on the market? We’ll have to look at the benchmarks to say for sure – but first, let’s quickly look at the specifications of these two coolers, straight from Scythe.

Cooler specifications

Packing and included contents

The Mugen 6 package houses a small brown box containing the accessories, with the fan below, protected by folded cardboard. At the bottom of the package is the heatsink, protected by molded foam.

Included with the coolers are the following:

• 120mm Scythe Wonder Tornado fan(s) and fan clips
• Single Tower Heatsink
• Mounting for modern AMD and Intel Platforms
• Thermal Paste and application tool
• PWM splitter cord (Mugen 6 Black Edition only)
• Full-size screwdriver
• Manual

LGA 1700 installation

The installation of the Mugen 6 is pretty standard and straightforward. 

1. Press the backplate against the rear of the motherboard and then secure it using the included plastic standoffs.

2. Next you’ll need to apply thermal paste to the CPU – if you're unsure how best to do that, see our How to Apply Thermal Paste primer.

3. Place the mounting bars on top of the standoffs and secure them with the included screws.

4. Place the heatsink on top of the CPU and secure it using the screws on the mounting bar. One of these screws you’ll need to thread with the screwdriver through the heatsink, as shown below.

5. Secure the fan or fans on the cooler using the included fan clips. If you’re using the Black Edition, you’ll need to connect the fans to the PWM splitter cord first, before connecting them to the motherboard.

Features of Scythe’s Mugen 6 and Mugen 6 Black Edition

Differences between the Mugen 6 and Mugen 6 Black Edition

The design of the heatsinks included with the Mugen 6 and Mugen 6 Black Edition are identical, save for the color (silver vs black). The other difference? The Black Edition includes two fans, whereas the standard Mugen 6 only includes a single 120mm fan.

Full RAM compatibility 

Some air coolers have compatibility issues with tall RAM – particularly if the first DIMM bank is used. That’s not an issue with Scythe’s coolers, which don’t interfere or overhang RAM in any manner. You can install any memory that’s compatible with your board here, no matter how tall the DIMMs are.

Six Copper Heatpipes

The Mugen 6 moves heat using six 6mm copper heatpipes, which is one or two less than some competing coolers. This initially caused me to worry that these units might underperform. But as you’ll see in our benchmarks, it performs well enough despite this deficit.

120mm Wonder Tornado fans

There’s more to a cooler than just the heatsink or radiator. The included fan or fans have a substantial impact on a cooler’s performance and are directly responsible for how loudly it runs.

Included with the Mugen 6 is Scythe’s 120mm Wonder Tornado fan, which has been optimized for thermal performance at lower noise levels. These fans include 9 swirl-shaped blades, with an improved blade-to-hub ratio compared to previous Scythe fans, and an upgraded frame body for improved durability. Scythe indicates its confidence in the quality of these fans with a lifespan rating of over 120,000 hours.

LGA1700 Socket Bending

There are many factors other than the cooler that can influence your cooling performance, including the case you use and the fans installed in it. A system's motherboard can also influence this, especially if it suffers from bending, which results in poor cooler contact with the CPU. 

In order to prevent bending from impacting our cooling results, we’ve installed Thermalright’s LGA 1700 contact frame into our testing rig. If your motherboard is affected by bending, your thermal results will be worse than those shown below. Not all motherboards are affected equally by this issue. I tested Raptor Lake CPUs in two motherboards. And while one of them showed significant thermal improvements after installing Thermalright’s LGA1700 contact frame, the other motherboard showed no difference in temperatures whatsoever! Check out our review of the contact frame for more information.

Testing methodology

Today's highest-end CPUs, whether Intel or AMD, are difficult to cool in intensive workloads. In the past. reaching 95 degrees Celsius or more on a desktop CPU might have been a cause for concern. But with today’s top-end CPUs, this is considered normal operation. Similar behavior has been present in laptops for years due to cooling limitations in tight spaces.

All testing is performed with a 23 degrees Celsius ambient room temperature. Multiple thermal tests are run on each CPU to test the cooler in a variety of conditions, and acoustic measurements are taken with each result. These tests include:

1. Noise-normalized testing at low noise levels

2. “Out-of-the-box”/default configuration thermal & acoustics testing

     a. No power limits enforced

     b. Because CPUs hit TJMax in this scenario, the best way to compare cooling strength is by recording the total CPU package power consumption.

3. Thermal & acoustic testing in power-limited scenarios

     a. Power limited to 175W to emulate a medium-intensity workload

     b. Power limited to 125W to emulate a low-intensity workload

The thermal results included are for 10-minute testing runs. To be sure that was sufficiently long to tax the cooler, we tested both Thermalright’s Assassin X 120 R SE and DeepCool’s LT720 with a 30-minute Cinebench test with Intel’s i9-13900K for both 10 minutes and 30 minutes. The results didn’t change much at all with the longer test: The average clock speeds maintained dropped by 29 MHz on DeepCool’s LT720 and 31 MHz on Thermalright’s Assassin X 120 R SE. That’s an incredibly small 0.6% difference in clock speeds maintained, a margin of error difference that tells us that the 10-minute tests are indeed long enough to properly test the coolers. 

Testing configuration – Intel LGA1700 platform

Thermal results without power limits

Without power limits enforced on Intel’s i7-13700K, the CPU will hit its peak temperature and thermally throttle with even the best air coolers. When the CPU reaches its peak temperature, I have measured the CPU package power to determine the maximum wattage cooled to best compare their performance. The results below do not include the best liquid coolers on the market, which are able to keep the CPU under TJMax (100C).

The single fan version of the Mugen 6 cooled 222W, on average, with no power limits enforced. This is just a little better than BeQuiet’s Dark Rock Pro 5 in the low-noise mode. The Mugen 6 Black Edition cools an additional 7W thanks to its second fan. This performance is between BeQuiet’s Dark Rock Pro 5 and DeepCool’s Assassin IV in their low-noise modes.

The maximum noise levels of both coolers are low, with the Mugen 6 reaching only 39.6 dBA with fans running at full speed. With two fans, the Mugen 6 Black Edition runs just a tad bit louder at 40.3 dBA. Both results are among the quietest results in our charts.

Thermal results with noise normalized to 38.2 dBA

Finding the right balance between fan noise levels and cooling performance is important. While running fans at full speed can improve cooling capacity to some extent, the benefits are limited and many users prefer a quiet system. With this noise-normalized test, I’ve set noise levels to 38.2 dba. This level of noise is a low volume level, but slightly audible to most people.

When I tested Scythe’s Fuma 3 last year, I was a bit disappointed with its noise-normalized performance compared to the competition. Both versions of the Mugen 6 perform better in this regard. The normal version of the Mugen 6 cools 220W in this noise-limited scenario, outperforming big-name rivals like Noctua’s NH-D15 and BeQuiet’s Dark Rock Pro 5. The Mugen 6 Black edition cools an additional 5W, with performance comparable to BeQuiet’s Dark Rock Pro Elite and Thermalright’s Frost Commander 140.

175W Cinebench results

Most coolers on the market can keep Intel’s i7-13700K under its peak temperature if the power consumption is limited, so for this test, we’ll be looking at the CPU’s actual temperature.

With a steady 175W load run on the CPU, the Mugen 6 with only a single fan performed on par with Scythe’s previous Fuma 3. The black edition performs 2C better, reaching only 56C over ambient. This places it on par with DeepCool’s Assassin 4S, Cooler Master’s MA824 Stealth, and many of the best coolers on the market.

Both versions of the Mugen 6 had excellent noise levels, with an average of 38.2 dBA – a noise reduction of 3.2 dBA compared to last year’s Fuma 3! These results are very good, tied with DeepCool’s Assassin IV & 4S for the second quietest coolers that we’ve tested in this scenario.

125W Cinebench results

The lowest power limit I test with Raptor Lake CPUs is 125W. This is a high enough limit to allow the CPU to maintain its base clock speeds even in the most intensive tests, and most coolers should be capable of keeping the CPU below TJ Max (the max temperature before throttling) – even Intel’s stock cooler can handle a load like this with ease.

Really, thermals do not matter in this scenario – but if you’re interested in them, CPU temperatures are shown in the graph above. Noise levels, rather than CPU temperature, are the most important factor here. These were ideal for both versions of the Mugen 6, never overpowering the ambient system noise of 37.3 dBA. What this means is that the cooler ran quieter than my system fans.

Conclusion

With the Mugen 6, Scythe brings performance and noise levels comparable to high-end models available from BeQuiet! and DeepCool – but at a more reasonable price. If you’re looking for a good-performing air cooler with low maximum noise levels, Scythe’s Mugen 6 and Mugen 6 Black Edition are well worth considering. 

There aren’t many other quiet coolers at this price level, but an alternative to consider would be Thermalright’s Phantom Spirit 120. It can dissipate slightly more watts for high-end CPUs, but also has higher maximum noise levels. 

Unlike some of its cooler competitors, Chiba Japan-based Scythe is a fabless company that partners with factories in China and Taiwan for manufacturing of its air coolers, fans and other PC hardware. The company has been delivering cooling products aimed largely at quiet performance for more than 20 years. 

Today we’ll be looking at Scythe’s successor to their very successful Fuma 2 air cooler, the Fuma 3. Will the improvements made by Scythe work well enough for it to earn a spot on our best coolers list? We’ll have to test it to be sure, but first lets look at this product’s specifications.

Specifications

Packing and Included Contents 

The box Scythe’s Fuma 3 arrives in isjust large enough to fit the contents inside of the package.

The inner contents are protected by molded foam, plastic, and molded cardboard to insure the cooler arrives undamaged.

Included with the package are the following:

• Full-size screwdriver 

• Fan clips for two fans
• Two fans, one of which is a low-profile/slim fan
• Dual tower radiator heatsink

• A small tube of thermal paste and paste spreader tool
• PWM splitter
• User Manual
• Mounts for all modern CPU sockets (including AM5 & LGA1700)

Installation on LGA1700 and AMD AM4 AM5

The installation process for the FUMA 3 is simple, no matter if you’re using an AMD Ryzen or an Intel-based platform. 

1. If you’re running an AMD Ryzen system, you’ll need to start by removing the default retention bracket. Intel users will need to apply the backplate to the motherboard.

2. Place the plastic standoffs atop the motherboard and place the mounting bar on top of them.

3. Intel users will next use the thumbscrews to secure the mounting brackets. AMD Ryzen users will use the included screws to secure the brackets. 

4. Apply thermal paste to the CPU.

5. Place the heatsink against the mounting bars and secure it with the included screwdriver. If you’re using a space-constrained SFF system, you can install the fans prior to this step, as there are holes for the screwdriver in one of the heatsink towers.

Designed With SFF and Mini-ITX in mind

Scythe has upgraded the Fuma 3 in a number of ways to make it a stronger and more effective cooler for both traditionally sized and small form factor (SFF) cases.

⋇ Full RAM compatibility 

Thanks to its slim fan, Scythe’s FUMA 3 won’t overhang any of your computer’s RAM slots, providing complete compatibility no matter the height of DDR4 or DDR5 modules.  

⋇ 154mm height for SFF compatibility 

Measuring only 154mm (just over 6 inches) tall, Scythe’s Fuma 3 should fit into most compact cases without a problem. Many higher-end air coolers will not fit in small cases due to height limitations. 

⋇ Recessed back heatsink for SFF compatibility

Some coolers, like DeepCool’s Assassin IV, don’t fit Min-ITX boards because they run into the back IO panel and VRM heatsinks of smaller motherboards. The fin layout of the Fuma 3 was designed with this in mind, and is fully compatible with mITX motherboards.

⋇ You can install the cooler with the fans attached

The Fuma 3 can be installed with it’s fans attached, which makes installation much easier in many space-constrained SFF cases using mITX motherboards.

⋇  It won’t cut you! 

Some might think this line is a joke, but Scythe’s Fuma 2 had ridiculously sharp edges that made it very easy for users to cut themselves. I’ve injured myself at least twice from that cooler’s prickly sides. The edges of the fins on the Fuma 3, on the other hand, are dull and do not present a safety hazard.

⋇  Reverse Rotating Dual Fans

There’s more to a cooler than just the heatsink or radiator. The bundled fans have a significant impact on cooling and noise levels. The Fuma 3 features two fans of different thicknesses. Both are 120mm Kaze Flex II fans, but one of them is the slim version of this fan. 

The mixed-size fans rotate in opposite directions to increase the total static pressure for better airflow through the fins and heatpipes. On the sides of each fan are arrows indicating which way the fan spins and the direction the fan should be installed. The fans are rated for over 120,000 hours of use, which in my opinion indicates a strong level of confidence from Scythe in the manufacturing process and the reliability of its fans.

Cooling Considerations

Modern CPUs, whether Intel or AMD, are difficult to cool in intensive workloads. In the past, reaching 95C+ on a desktop CPU might have been a cause for concern – but with today’s processors, it is considered normal operation. Similar behavior has been present in laptops for years due to cooling limitations in tight spaces. 

Since last fall, Tom’s Hardware has brought you cooling reviews using one of the most power-hungry desktop CPU on the market – Intel’s flagship i9-13900K. To give you an idea of what it takes to cool Intel’s behemoth, we’ve tested it with a variety of coolers from basic low end air coolers like the Amazon Basics CPU cooler, to high-end 420mm AIOs such as Corsair’s iCUE H170i Elite.

While it’s nice to see how Intel’s flagship responds to different levels of cooling, those results don’t always correlate with lower-tier CPUs. Today’s review features two CPUs more commonly purchased by end users:  AMD’s Ryzen 7 7700X and Intel’s i7-13700K.

LGA1700 Socket Bending

Note there are many factors other than the CPU cooler that can influence your cooling performance, including the case you use and the fans installed in it. A system's motherboard can also influence this, especially if it suffers from bending, which results in poor cooler contact with the CPU. 

In order to prevent bending from impacting our cooling results, we’ve installed Thermalright’s LGA 1700 contact frame into our testing rig. If your motherboard is affected by bending, your thermal results will be worse than those shown below. Not all motherboards are affected equally by this issue. I tested Raptor Lake CPUs in two motherboards. And while one of them showed significant thermal improvements after installing Thermalright’s LGA1700 contact frame, the other motherboard showed no difference in temperatures whatsoever! Check out our review of the contact frame for more information. 

Testing Methodology

All testing is performed at a 23C ambient room temperature. Multiple thermal tests are run on each CPU to test the cooler in a variety of conditions, and acoustic measurements are taken with each result. These tests include:

1. Noise normalized testing at low noise levels

2. “Out-of-the-box”/default configuration thermal & acoustics testing.

     a.) This means no power limits on Intel’s i7-13700K, and AMD’s default power limits on AMD’s Ryzen 7 7700X.

      b.) Because CPUs hit Tjmax in this scenario, the best way to compare cooling strength is by recording the total CPU package power consumption.

3. Thermal & acoustics testing in power-limited scenarios.

      a.) With Ryzen 7 7700X, I’ve tested with limits of 95W and 75W enforced.

      b.) On Intel’s i7-13700K, I’ve tested with limits of 175W and 125W enforced.

The thermal results included are for 10-minute testing runs. To be sure that was sufficiently long to tax the cooler, we tested both Thermalright’s Assassin X 120 R SE and DeepCool’s LT720 with a 30-minute Cinebench test with Intel’s i9-13900K for both 10 minutes and 30 minutes. The results didn’t change much at all with the longer test: The average clock speeds maintained dropped by 29 MHz on DeepCool’s LT720 and 31 MHz on Thermalright’s Assassin X 120 R SE. That’s an incredibly small 0.6% difference in clock speeds maintained, a margin of error difference that tells us that the 10-minute tests are indeed long enough to properly test the coolers.

Testing Configuration – Intel LGA1700 Platform

Testing Configuration – AMD AM5 Platform

Thermal Results with noise normalized to 38.2 dBA

Finding the right balance between fan noise levels and cooling performance is important. While running fans at full speed can improve cooling capacity to some extent, the benefits are limited and many users prefer a quiet system.  

In this test where the fans have been set to low noise levels, Scythe’s Fuma 3 slightly outperformed other coolers of its class, like Cooler Master’s Hyper 622 Halo, when paired with hotter CPUs like Intel’s i7-13700K.

No Power Limits Thermal Results

Without power limits enforced on Intel’s i7-13700K, the CPU will hit its peak temperature and thermally throttle with even the strongest of air coolers. In this test, we measure the total amount of watts the cooler is able to dissipate from the CPU.

When we looked at the earlier results which take noise levels into account, it was pretty clear that the higher-end coolers like MA824 Stealth showed an advantage with a performance increase over the Fuma 3 by 14W+. Things got interesting when we cranked up the fan speeds – the Fuma 3 managed to cut that performance gap down to 6 watts. That’s still trailing behind the kings of cooling, but not by much!

Now the Fuma 3 does run at slightly higher noise levels to achieve this level of performance, but we’re not talking huge differences here. DeepCool’s Assassin IV and Noctua’s NH-D15S both measured at 43.4 dBA when I tested them; Scythe’s Fuma 3 measured 44 dBA. That’s a moderate noise level which won’t bother most folks, and it’s quieter than most other coolers you can find for around $50, which usually run between 45-48 dBA.

175W Cinebench Results

Most coolers on the market are able to keep Intel’s i7-13700K under it’s peak temperature if the power consumption is limited, so for this test we’ll be looking at the CPU’s actual temperature.

With this slightly restricted workload, the Fuma 3 performs similarly to other air coolers, with a temperature of 58C over ambient. Where Scythe’s cooler stands out are the noise levels. At only 41.4 dBA it was much quieter than other coolers of its price class, which typically run 44 dBA or louder.

125W Cinebench Results

The lowest power limit I test with Raptor Lake CPUs is 125W. This is a high enough limit to allow the CPU to maintain it’s base clockspeeds even in the most intensive tests, and most coolers should be able to keep the CPU below Tjmax – even low-end coolers.

With a thermal measurement of 45 degrees C over ambient, the thermal performance of Scythe’s Fuma 3 is just a single degree behind heavyweight coolers from Noctua and CoolerMaster. But in this scenario, thermal measurements are largely academic. What’s more important at this restricted TDP are noise levels, and I measured 38.9 dBA in this test. This is a very good result, amongst the best I’ve seen. 

AMD Ryzen 7 7700X Thermal Results

It’s great to see how coolers perform with hotter CPUs like Intel’s i7-13700K, but that performance doesn’t always directly translate to how other CPUs will operate with the same coolers. Some coolers might perform better – or worse – depending on the CPU it’s paired with. Today’s review I’ve includes AMD’s Ryzen 7 7700X to show how coolers might respond with more commonly used CPUs.

Thermal Results with noise normalized to 36.4 dBA

After equalizing the noise levels to 36.4 dBA, the Fuma 3 managed to cool an average of 120W during the tests of AMD’s Ryzen 7700X. That’s a fantastic outcome, just a bit better than BeQuiet’s Dark Rock Pro 4 and just a tad behind Cooler Master’s MA824 Stealth. That’s pretty impressive for a cooler that’s significantly cheaper.

Maximum Cooling Capacity with maximum fan speeds

Next up we wanted to see how the cooler handles a maximum heat workload, so we let the fans run at their full speeds. During this test, Scythe's Fuma 3 managed to cool 124W, just barely edging out BeQuiet's Dark Rock Pro 4 - though it did make a bit more noise in the process. Still, it's a pretty good result, only 6W away from the best air-cooling performance I've seen with AMD's Ryzen 7 7700X. 

At 44.6 dBA, the Fuma 3’s peak noise levels are quieter than most other air coolers of its price class, which again generally range from 45-48 dBA.

Thermals and Acoustics with a 95W Power Limit

You won’t always push your CPU to its absolute limits or maximum power draw, so it’s a good idea to test coolers across different power limits. For a user of AMD’s Ryzen 7700X, 95W will represent loads more demanding than gaming but less demanding than rendering. In these scenarios, noise levels are generally considered more important than cooling performance.

The Fuma 3 performs just as well as we’ve seen from the top-tier air coolers in this scenario when it comes to thermals. As for noise levels? By the end of the test, the Fuma 3 reached 44.6 dBA – just as loudly as it operates in full load conditions. I would consider this a moderate noise level, not quiet but not loud in any sense of the word.

Thermals and Acoustics with a 75W Power Limit

With power draw reduced to 75W on AMD’s Ryzen 7 7700X, this thermal load shouldn’t be difficult for most coolers to cool. This is roughly the amount of power Ryzen 7 7700X CPU will use during gaming, and it’s also the maximum power consumption of AMD’s non-X Ryzen 7 CPU.

At this lower level of power consumption, cooling difficulty isn’t hard at all; even the most basic coolers should have no problems here. In this situation, the temperature of the CPU isn’t very important. Noise levels are much more important here. 

When tied to the default fan curve of ASRock’s B650e Taichi, noise levels reached 38.9 dBA for Scythe’s Fuma 3. This is a low, hushed noise level that shouldn’t be a bother to anyone.

Conclusion

Scythe’s Fuma 3 offers great performance, competitive with high-end air coolers, and comes at a value-oriented price tag of only $49 USD. And unlike many of those larger coolers, the Fuma 3 fits well into space-constrained SFF cases.

Scythe is increasing its CPU cooling lineup with its Shuriken 2 SCSK-2000, as reported by TechPowerUp this week. The cooler is a smaller variant of its Big Shuriken line of coolers and comes as a simple top-down CPU cooler with a slim, 92mm PWM fan.

The Shuriken 2 fan can spin at speeds between just 200 and 2,500 RPM, meaning it can operate very silently when the system is idling but still dissipate up to 100W, which is a perfectly good figure for a low-profile CPU cooler. CPU socket support is said to include AM4 and LGA115x. 

The heatsink itself is made with a nickel-plated copper cold plate, which pushes the heat to the fin stack through four 6mm heatpipes. Add all that up, and you’ve got a cooler that weighs 350g (0.8 pounds), and has a  93 x 94 x 54mm (WxDxH) footprint. 

With such dimensions and performance, it's a perfect cooler for use in small form factor systems witt a Mini-ITX motherboard. You should get a solid increase in thermal performance over a standard boxed cooler, which would help your CPU maintain its boost frequencies for longer.

The cooler is reportedly coming out early next month. Pricing wasn’t revealed, but we expect it to cost between $30 and $40.

Features and Specifications

Zalman has been a cooling mainstay in the PC building community for decades, offering up a variety of coolers, from sculpted, steampunk-esque copper works of art to benchmark-breaking workhorses with simpler designs. While the CNPS10X Optima II bares the namesake of the same parent company, it pales in comparison to the best Zalman products that came before it.

Zalman CNPS10X Optima II Specifications

Features

Zalman ships the CNPS10X Optima II with the usual assortment of plated fasteners and tension brackets we’re accustomed to, including a universal backplate, PWM to 4-pin/3-pin splitter cable and a packet of ZM-STG2M thermal compound.

While the CNPS10X Optima II is listed as having RGB lighting, it should be noted that there isn’t an included control module or set of interface cabling for either standalone or motherboard-capable management.

As a quad-heatpipe design with a direct contact base, the Zalman CNPS10X Optima II is similar to other coolers of its type. The aluminum fin stack of the cooling tower provides low resistance to airflow produced from the dual-blade design, 120mm hydraulic bearing fan that’s rated up to 61.5 CFM at 1500 RPM.

An elegant shroud encases the top and each side of the Optima II, while also providing self-tapping screw eyelets for fan mounting. Recesses in the top allow for the embedded RGB lighting to emanate through opaque sections of the shield.

As previously mentioned, the CNPS10X Optima II is RGB capable. However, illumination comes equipped as a single factory-set ‘spectrum lighting’ pattern that is powered exclusively by the fan header. In short, this means the RGB effects for the fan is always on, although one could opt to leave the top-shroud lighting module disabled by choosing not to connect the 3-pin (fan type) pigtail for it.

As a direct-contact heatpipe solution, the Zalman CNPS10X Optima II mates the handsome, brushed base of the cooler with the milled heatpipes into the mounting block. The contrast of metals around the cooler base provides an elegant, highly-engineered look, while the shark-fin plastic tabs of the lower cooling shroud (on each side) provide clear indication to the origins of our memory DIMM clearance concerns.

Installation of the mounting brackets requires some PC hardware gymnastics in the form of unscrewing both sides of the mounting base’s fasteners, while not completely removing them. This allows the base plate bracket slack on each side to slip the tension brackets over two alignment tabs on either side, while aligning gaps in the brackets with the fastener screws.

While the alignment tabs do help maintain bracket orientation during the re-torqueing process of the machine screws, there remains a small bit of play in the bracket system, which can require a few attempts at getting this step right. If the brackets are not correctly aligned, securing to the motherboard mounting posts proves a bit daunting.

After the bracket ballet, installation of the Zalman CNPS10X Optima II is relatively straightforward to complete. The self-tapping screws for the fan mounts can require a good bit of force to get started, which also requires some significant pressure (and great care) in order to secure them in place without applying excessive force with your screwdriver inside a PC case.

Our recommendation is to test fit the fan to the cooler prior to installing to allow the fan screws to pre-tap into the shroud first, since the fan cannot be in place when the cooler is initially being mounted to the motherboard. This lessens the amount of lateral force needed to secure the fan’s four mounting screws. But be prepared to still provide support on the cooler’s opposite side. Pro tip: a stubby Phillips-head screwdriver works much better here than those with longer handles.

Clearance was very limited during our installation process and we needed to re-seat the Optima II three times in our attempt to get the cooler shroud low enough on our MSI X99 XPower AC motherboard PWM heatsink to allow the heatpipes to make good contact with the CPU heat spreader. Initially, the shroud was causing the side of the cooler to lift off of the processor while also causing us some alignment issues with the mounting hardware.

A 90-degree turn to orient the heatsink and cooling fan up/down on the Optima II also wasn’t possible as the same clearance issues were also present, but this time, we found installation restricted by our memory DIMMs. Our best course of action was to re-orient the Zalman cooler to its original, vertical (front to back) airflow configuration while being very meticulous in our movements as we anchored it.

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Testing Results and Conclusion

Comparison Products

Benchmarks

Testing was performed on our Intel i7-5930k test bench, overclocked to 4.20 Ghz at 1.20v. We will compare the Zalman CNPS10X Optima II with Arctic Freezer 34 eSports DUO, the Scythe Kotetsu Mk.II TUF and the Cooler Master Hyper 212 RGB Black Edition, as these all represent similar mid-tower heatpipe cooling solutions.

Thermal load testing shows the Zalman CNPS10X Optima II struggled on our overclocked, 6-core high-end desktop CPU. At 50% fan speeds, we witnessed some CPU throttling due to temperatures bouncing up against the processor’s thermal threshold.

Thermal load testing often provides some insight into measured fan RPM. In this instance, the Zalman and Scythe each listed slower fans of the testing group and were outpaced in thermal performance by the higher-RPM fans on each the Arctic Freezer 34 eSports DUO and Cooler Master Hyper 212 RGB Black.

Fan speed often hints that higher RPM fans will generate elevated decibel levels. However, despite having a wide range of speeds across the testing group, we’re seeing a relatively tight grouping of measured decibel readings.

Acoustic efficiency evaluates thermal performance and relative noise measurements to give an insight into how effective a CPU cooler is as it is utilized in equivalent load scenarios. This chart favors a cooling solution that excels in thermal performance, measured acoustics, or both. For our comparison group, we saw very similar decibel readings from all coolers, so individual thermal load performances creates more separation across the board.

Priced at $45, the Zalman CNPS10X Optima II is the most expensive of the testing quartet, but just barely. Measuring the acoustic efficiency value of the CNPS10X Optima II while accounting for retail pricing further skews the performance value chart in the comparison. By contrast, the Arctic Freezer 34 eSports DUO posts strong marks in our chart due to its exceptional thermal load performance, modest noise levels and slightly lower price.

Thermal imaging from our FLIR ONE Pro is very similar between 50% and 100% fan speeds, primarily due to the insulating properties of the plastic shroud around the Zalman CNPS10X Optima II. However, around the perimeter of the cooler we can see slightly lower temperatures on the adjacent hardware and motherboard features at 100% speed as compared to 50%. Also interesting to see is the expansion of the heat bloom on the roof of the chassis above the cooler where the higher fan speeds dispel more thermal load out of the cooler and into the surrounding hardware above and to the rear of the Optima II.

Warranty Oddities and Bottom Line

Moving past performance, one thing of note: We had some difficulty finding actual warranty details around the Zalman CNPS10X Optima II. Zalman’s own website and the included documentation each seemed barren of claim information, until we found what appeared to be the warranty information in Chinese in the boxed product documentation and in downloadable PDF. A quick run-through on Google translation services shows that Zalman provides a 1 year warranty for the cooler, although this is clearly not the most reliable or convenient way to suss out warranty details.

The Zalman CNPS10X Optima II trails behind other solutions in the same price range, and its physical design makes it difficult to recommend compared to some of its peers. Outside of the thermal load performance gap, simple details such as the shroud clearance and RGB lighting limitations are obvious let downs when most solutions adequately account for these technicalities.

The Zalman CNPS10X Optima II does potentially appeal to system builders who wish to follow a color scheme featuring a prominently pearly cooler design and who might be content with factory CPU clock speeds and lower core counts. But those who are performance-driven power users will want to take a closer look at alternatives in the same pricing tier, like Arctic’s Freezer 34.

Image Credits: Tom's Hardware

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The sequel to its renowned Fuma CPU cooler, Scythe’s Fuma 2 is designed to provide big air cooling with far fewer space conflicts. This new model announced today uses slanted heatpipes to provide rearward offset, which, along with its slim front fan, fits behind the memory of most motherboards.

Meanwhile, shortened bottom fins at the back allow it to fit both before and above the rear modules of quad-channel motherboards.

The purpose of all this offset and slimming was to lower the height of its Kaze Flex 120 x 15mm and 120 x 25mm fans. This allowed the company to produce the oversized cross-flow sink with a total height of only 154.5mm for improved clearance of a case’s side panel.

Rated by Scythe to have 15% more thermal capacity than its predecessor, model SCFM-2000 fits most consumer motherboards with Intel CPU sockets from LGA 775 onward, and most AMD consumer sockets from AM2 onward (excluding TR4). It’s currently available for $60 at Newegg.

Photo Credit: Scythe

For those who are considering building a small form factor (SFF) PC, another CPU heat sink has hit the market vying for your dollars. Today, Scythe added to their already long line of CPU cooling solutions with the Big Shuriken 3 (BS3). The BS3, like its predecessor, is designed for SFF systems using an asymmetric design said to yield uninhibited access to RAM modules. The new model appears to have a lot more beef to it, along with a new mounting system that should keep that low-volume SFF running cool.

Scythe Big Shuriken 3 CPU Cooler Specs

What looks to be the biggest difference between the BS2 and BS3 is the the size of the fin array. The fin array was extended down into the heat pipes and closer to the base of the cooler. This increases fin area and, in theory, provides better cooling in a shorter package. The BS2 used five heat pipes looping up to the fin array, and the BS3 also uses five, but instead of looping out both sides of the heat sink to make contact with the fins, it snakes through the much thicker fins on one side. 

The BS3 includes the recently developed Kaze Flex 12015 mm slim fan (the 15 represents the thickness) to move air down through the updated heat sink. This fan is able to run from 300-1800 RPM with up to 50.79 CFM and 1.35 mmH20. Using this type of fan, the total height on the unit is 69 mm, cut almost in half compared to the BS2. The cooler also has an option for swapping the included 15 mm fan to a fan with a more common 25 mm thickness for increased cooling performance with a slight increase in overall height.

The BS3 also brought with it an improved mounting solution from the clip (AMD) or pushpins (Intel) used on the BS2. In its announcement today, Scythe claimed the new HPMS III mounting system guarantees a convenient and user-friendly installation process and provides perfect contact pressure on all current sockets and platforms.

While we do not have one in hand to confirm these statements, the new mounting solution at least looks to be a lot more robust than the previous Big Shuriken. To that end, the cooler supports Intel LGA 775 115x / 1366 / 2011(v3) / 2066 and AMD AM2(+) / AM3(+) / AM4 / FM1 / FM2(+) sockets; TR4 (for AMD Threadripper processors) need not apply.

The Scythe Big Shuriken 3 is available now, including at Amazon and Newegg, for $44.99 / £49.76.

Features and Specifications

Scythe’s second warrior for the TUF Gaming Alliance arena is a villainous-looking, quad-heatpipe cooler utilizing a 120mm RGB PWM fan designated as the Choten.  Featuring a compact downdraft design and TUF Gaming Alliance graphics, the $40 (£31) Scythe Choten easily appeals to the budget-centric system builder focused on compact designs and synchronized RGB lighting effects.  All of the impressive presentation comes at a price, though, as thermal performance falls behind other coolers of similar size and price.

Scythe ships all the standard hardware for mounting the Choten atop nearly all modern AMD and Intel processors, other than Threadripper. Besides the reinforced plastic backing plate, the rest of the cross bracket supports, bracing and machine screw hardware is silver, plated and rather shiny.  Best of all, other than the 2-year warranty, is the inclusion of a small packet of thermal compound to expedite installation of the Choten once it lands on your desk, ready for your build.

Specifications

The top-down view of the Choten shows the set of quad-heatpipes as they route through the cooling tower body. While it might look like three, or even six pipes are visible, there are only four in total.  The visual puzzle can be accounted for by the inner and outer pairs being offset and of different lengths.  The outer heatpipes, being much longer are actually terminated by the chrome caps of the outer and center caps, while the inner pair are much shorter in overall length, yet only the innermost end of the heatpipe terminates with a shiny, silver cap; the other end is hidden, nestled within the cooling fin tower.

The heatpipes integrate into the mounting base of the Choten which accepts the mounting crossbar for securing the cooler to the mounting braces.  The chevron-like side pieces are actually a method of interlocking the cooling tower fins to allow for cutouts which allow torquing of the mounting screws.

The RGB Scythe Kaze fan comes equipped for control via standard 4-pin PWM and RGB headers. The opaque fan blades and hub provides a uniform, glowing effect thanks to the RGB LED lighting contained within, although the Choten does not provide a stand-alone lighting controller, so you’ll need to use a supported RGB capable motherboard or bring your own RGB lighting effects controller.

A highly polished mounting base awaits mating to your AMD or Intel CPU of choice.  The chevron interlocks show the selection of cooling fins that allow for the access ports between the heatpipes. Speaking of heatpipes, the shorter leg of the hidden inner pair is easily seen tucked away in the center of the cooling tower itself.

DIMM clearance isn't an issue thanks to the Choten's high base clearance. With the heat sink installed, the cooling fan simply snaps into a recess in its cooling fins, and is then secured with wire mounting clips on either side.

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Image Credit: Tom's Hardware

Testing Results and Conclusion

One primary benefit of testing a multitude of CPU coolers is that we always have large volumes of test data on hand for comparison when we need to evaluate new components. Result data taken from our overclocked hex-core, Intel i7-5930k at 4.2Ghz and 1.20v on our MSI X99S XPower AC motherboard provides plenty of thermal load to push the limits of every CPU cooler we test.

We’ll be comparing the Scythe Choten TUF Gaming Alliance with its sibling, the Scythe Kotetsu MkII TUF Gaming Alliance, the Cooler Master MasterAir MA410M TUF Gaming Alliance and the be quiet! Dark Rock 4.

Thermal load performance of the Scythe Choten fares only slightly better than that of the Kotetsu MkII, but trails behind that of the Cooler Master and be quiet! coolers by more than 20°C.

Slower fan speeds are tracked for both the Scythe Choten and the Kotetsu MkII, both of which utilize the same 120mm Kaze RGB Kaze fan.  The be quiet! Dark Rock 4 spins a 135mm fan as its primary armament.  And of course, the Cooler Master MA410M utilizes a 120mm dual-fan setup, with each topping out at over 2000 RPM.

Higher fan speeds almost always result in higher relative noise levels, and the low-RPM values on the Scythe Choten TUF Gaming Alliance put it in position just barely higher than the whisper-quiet Dark Rock 4.  Likewise, the twin-prop setup of the Cooler Master MasterAir MA410M shows what dual high speed fans nets you in terms of noise levels.

Even with a higher range of overall thermal results, the low noise levels benefit the Scythe Choten well enough to provide a proper balance between cooling and acoustics.  The be quiet! Dark Rock 4, having the best overall thermal performance and the lowest registered noise levels of the group easily pushes ahead in our acoustic efficiency rating.

Once we factor in the low cost of the Scythe Choten ($40/£31), the chart really swings into favor for the downdraft heatpipe cooler and its sibling, the Kotetsu MkII.  Both the Cooler Master MA410M and the be quiet! Dark Rock 4 take hits on our chart from having higher overall cost.

Thermal imaging from our Flir One Pro shows a slight increase through the cooling tower in an almost transparent view though the top view of the Choten’s downdraft design.  At 50 percent fan speeds, there is noticeable heat bloom variation through the core of the cooling tower compared to the same region with the fan set to full speed.  The 100 percent view also shows more heated turbulence around the perimeter of the cooler, signifying dispersion of heated airflow from the increased blade speed.

The unique design of the Scythe Choten provides a welcome display of the inner workings of a heatpipe cooler, even if it isn’t the outright best at cooling high end desktop (HEDT) CPUs shouldered with large overclocks.  However, the Choten is quite suitable for entry-level builds and moderate overclocking for most modern quad core CPUs with a stock TDP under 95 watts.  The TUF Gaming Alliance theme also provides a bit of punchiness and attitude to any build, while RGB lighting allows it to mesh easily with any color theme you choose.

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Features and Specifications

Designed to suit the needs of budget gaming and entry-level overclocking markets, bright color accents align Scythe's Kotetsu Mark II to Asus' TUF Gaming Alliance. Relying solely on the lower heat outputs of mainstream processors and the integrated RGB control of Tuf Gaming series motherboards, the Kotetsu MkII TUF Gaming Alliance cooler adds a bright RGB splash to your armor-themed build, at a reasonable price.

Scythe joins the TUF Gaming Alliance with the branded Kotetsu Mark II RGB heatpipe cooler, featuring a quiet-running 120mm RGB cooling fan. 

It comes bundled with typical tower cooler mounting hardware including plated brackets, mounting posts, machine screws, a sturdy backplate and knurled securing nuts. An additional set of spring mounted fan clips are included to allow a secondary fan to be used for push/pull airflow configuration. Scythe have even dropped in a small packet of thermal compound to ensure you are able to get the cooler up and running as quickly as possible.

Specifications

The quad-heatpipe design used on the Kotetsu Mark II uses an offset pattern to allow balanced thermal transfer between the cooling pipes and the cooling fin tower. The mounting crossbar is secured across the mounting base which also includes a heatsink design to help assist in dissipation. The top fin cap is decorated with TUF Alliance digital camouflage graphics and provides a welcome touch of attitude.

A slight offset can be seen from the side, where the cooler is shifted approximately half an inch (12.7mm), although it is only assumed to account for single-fan setups.  Plating on both the heatpipes and cross bracket mimics that of brilliant chrome and while offering the same gleaming sparkle, they also pick up fingerprints just as easily.

The 120mm RGB cooling fan on the Scythe Kotetsu Mark II is controlled by 4-pin PWM and 4-pin standard RGB. Rated up to 1,200 RPM, the cooling fan provides quality lighting glow from the opaque fin hub while operating at relatively low noise levels. System builders will need to ensure that they have an open 4-pin RGB motherboard header or find a standalone RGB color controller, as the Kotetsu does not ship with its own device.

The four heatpipes collect below the cooling tower and sit between the mounting block and a plated IHS surface mating block making it the primary thermal conduit between CPU below and cooler above. A near perfect finish is adorns the base contact block, keeping with the brilliant, reflective theme seen on the cooling pipes.

The Kotetsu's interlacing thermal cooling fins and heatsink-inspired mounting block can be seen in a bit more detail. Spring tensioned machine screws are affixed to the mounting crossbar which ease the installation process.

Once installed, the Kotetsu offers good memory DIMM clearance on both sides, and the ability to clip the fan to the cooler at various heights provides additional adjustment, if needed. All of the mounting hardware can be easily accessed while the fan is removed.
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Image Credit: Tom's Hardware

Testing Results and Conclusion

Our comparison tests are derived from current and prior CPU cooler testing using standardized methods for benchmarking and gathering data on our hex-core, Core i7-5930K running at 4.2 GHz. We will be comparing the Scythe Kotetsu MkII TUF Gaming Alliance with the Cooler Master Hyper 212 RGB Black, the be quiet! Dark Rock 4 and Cooler Master MasterAir MA410M TUF Gaming Edition.

The reason we’ve stuck with our 5930K primarily is because it’s quite good at what it does: generating a lot of heat with great consistency when heavily loaded.  Its fixed clock was designed to push the absolute limits of 120mm single-fan/single-tower coolers and adequately prove the performance advantages of larger units.

Thermal loads from our mini-blast-furnace i7-5930K CPU nearly overloads the Scythe Kotetsu Mark II cooler at both full and half speed fan settings.  There’s just no other way to say it, but the Kotetsu Mark II cooling performance is entry-level at best, at least by our test standards.

Looking at the thermal load charts against the fan speed chart, the Scythe Kotetsu Mark II fan speed does happen to be the lowest of the comparison group, its 100 percent setting hovering just barely above the 50% speeds turned in by both Cooler Master products. The fan on the be quiet! Dark Rock 4’s low RPM value happens to be from a 135 mm model, while all other fans in the testing group are 120 mm diameter.

Those moderate fan speeds from the Kotetsu MarK II make a big difference in terms of ambient noise levels, sliding in just barely above the whisper-silent Dark Rock 4. By comparison, the twin-turbine Cooler Master MA410M TUF is a deafening shuttle launch.

Factoring cooling performance with noise levels, the Kotetsu Mark II doesn’t fare as well despite its great acoustics. The inverse is exactly true for the MasterAir MA410M TUF with good cooling performance and worst registered noise levels.

Flash forward to the performance value chart where the Kotetsu makes a sweeping charge to finish out relatively strong for the testing group, primarily due to its very friendly $40 (£31) price point.  While the Dark Rock 4 and MA410M do perform much better in thermal and acoustic tests, pricing equalizes the playing field when all points are used for comparison.

Thermal imaging from our Flir One Pro show a relative heat bloom at 50 percent fan speed as compared to full speed, although not as much of a difference as we’d expect considering the reported core temperatures.  This could point to something more fundamental with how the heatpipes are able to absorb loads from the CPU and dissipate effectively through the cooling tower fins.  Otherwise, we’d see a definitive spike in thermals in the cooling tower, indicating that the Kotetsu’s fan isn’t up to snuff.

Scythe’s Kotetsu Mark II TUF Gaming Alliance cooler leaves us with some debate, though.  On one hand, it performs rather poorly under high loads from our overclocked six-core i7-5930K. While it could be argued that many current-gen 4-8 core CPUs won’t likely be pushing TDPs nearly as high, we still must consider all possibilities are indeed, possible. 

On the other hand, the handsomely low price of $40 (£31) makes it very attractive to budget system builders and entry level overclockers.  In addition, the TUF Gaming Alliance theme adds a bit of aesthetic allure to that that as well. Low costs often play very well into what many budget gamers are looking for, although the Cooler Master Hyper 212 RGB black performs better and offers an included RGB controller, while also being priced the same as the Scythe Kotetsu Mark II TUF Gaming Alliance.

The Kotetsu looks to be a solid fit for the budget gaming community, which is a bona fide commitment, considering the number of builds going online these days with four cores or fewer onboard. But we wish it offered an RGB controller, better HEDT performance or a lower price.

Want to comment on this story? Let us know what you think in the Tom's Hardware Forums.

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Features and Specifications

Big, monolithic air coolers are known for relying on multiple heatpipes and stacks upon stacks of individual cooling fins to provide vast surface area to effectively dissipate thermal loads. Of these, the newly released SCNJ-5000 Ninja 5 is the latest thermal assassin from the twin-blade cooling company, Scythe.  Sporting a pair of low-speed 120mm fans over a handsomely designed, interleaved, two-tone cooling fin stack, the Ninja 5 presents itself as an imposing heatpipe tower boasting near-silent operation, but still lands a little short in outright thermal performance for a cooler of its dimensions.

Offering support for nearly every modern CPU socket from both AMD and Intel, the Ninja 5 can sit atop just about every processor except Threadripper.  Shipping with a fairly-standard cooler mounting kit, the Ninja 5 goes a bit further with the inclusion of a syringe of thermal compound and Phillips head screwdriver.  Gone are the excuses for ‘not having everything you need’ to install this cooler.

Specifications

The Scythe Ninja 5 features six, nickel-plated heatpipes that run vertically through the entirety of its 41 interleaved aluminum cooling fins, which can be seen overlapping through the center of the stack.  The base of the cooler integrates a broadly-grooved, mini-heatsink that integrates with the mounting arm of the cooler.  Each of the six heatpipes are symmetrically aligned and offset to allow linear airflow around them.

The nickel plated base of the cooler cocoons each of the six, 6 mm diameter heatpipes between the base block and the mounting top plate.  The center bar is permanently secured to the cooler base and holds a pair of spring mounted machine screws in position to secure to the hardware CPU socket crossbars. 

The strategic slotting of the cooler’s heatsink fin stack provides access for the long, narrow Phillip’s head screwdriver to reach each of the machine screws from above the cooler when securing the cooler to the mounting braces.

Twin Scythe Kaze Flex 120 mm fans adorn the front and rear of the cooling tower and are PWM capable.  Rubberized mounting elbows eliminate vibration noise while the fans are affixed using a pair of wire-spring clips.  The Kaze Flex fans are rated at 43 CFM of airflow and a max speed of around 800 rpm, however in our tests, we found them to peak at just a smidge over 900 rpm.

It becomes difficult to remember that our MSI X99S XPower AC motherboard is actually a full, E-ATX motherboard with the Ninja 5 (and fans) consuming nearly the entire width of the board above the CPU, from side to side. 

The cooler’s CPU socket bracing builds off either the included mounting backplate or, in our case, the motherboard’s integrated mounting threads. Then, using the handy magnetic-tipped screwdriver provided by Scythe, you can easily slip between the aluminum cooling fins to find the machine screws, secure the cooler and snug it down. 

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Testing Results and Conclusion

Comparison Coolers

Using our hex-core Intel i7-5930k clocked to 4.2 GHz  at 1.2 volts, we can compare the Ninja 5 against other coolers which have graced our test bench.  This means that large, heatpipe-based air towers are the focus of our attention and, by including testing results of the FSP Windale 6, be quiet! Dark Rock Pro 4 and the Cooler Master MasterAir MA620P TUF Edition, we can build an effective comparison between these coolers evaluation of the big Scythe cooler, the Ninja 5.

Outright thermal load performance of the Ninja 5 lags a bit behind the other products in our testing quartet but that does not tell the entire story as we’ll see in a moment.  Strong numbers from the be quiet! Dark Rock Pro 4 and the FSP Windale 6 look promising while benchmark tallies between the Scythe Ninja 5 and Cooler Master MA620P TUF battle head to head, just to keep up.

CPU coolers depend on overall surface area as a primary cooling commodity to allow for their fans to dissipate thermal loads away from the cooling fins and into the surrounding area.  Interestingly enough, the Ninja 5 relies on lower-speed 120 mm fans than its competitors, which might detract from overall cooling potential to compensate for low noise levels.  Rated at 800 rpm, the dual cooling fans on the Ninja 5 were found to outperform their rated speeds, peaking at just over 900 rpm in our tests.

Even with the lowest fan speeds of the testing group, the Ninja 5 still cannot manage to turn in the lowest noise levels, although anyone would be hard-pressed to notice a PC in a room with any of these large coolers installed.  In fact, other ventilation case fans and traditional platter hard drives will likely draw more attention than any cooler in this list.

With decibel levels being relatively equal for registered noise and decent thermal load ratings, the Scythe Ninja 5 manages to hold its own against the performance of the FSP Windale 6 and the be quiet! Dark Rock Pro 4, while the Cooler Master MasterAir MA620P TUF Edition takes an efficiency hit due to volume differences.

Combining unit cost with overall cooler performance, the Scythe Ninja 5 begins to center itself in the middle of the pack due to relatively moderate pricing at $60 (£47) to match that of the Cooler Master MA620 TUF while only the FSP Windale 6 is priced lower.  The Dark Rock Pro 4 easily reaches into the upper echelon of bleeding-edge enthusiast performance, while also demanding a price tag that matches these expectations.

Thermal imaging from our FLIR ONE Pro shows only a slight difference between full and half-speed fan settings, but you can see that the cooling fins retain more thermal energy at 50 percent of the maximum rpm.  Nearby components, including the ambient air and chassis roof also have elevated readings.

Bottom Line

With all things considered, the Scythe Ninja 5 represents a decent air cooling option for most moderately-overclocked CPUs, but it does struggle with high-end desktop processors and big overclocks.  Strangely enough, the same can be said about the Cooler Master MasterAir MA620P TUF as both units perform and are priced nearly the same.

Unfortunately, the 800 rpm fans limit the Ninja 5's cooling potential. If having a quiet system is a higher priority, then the the Scythe Ninja 5 is a solid choice. However, if you need top-notch cooling, you should go for a product with better airflow like the be quiet! Dark Rock Pro 4, which is actually even quieter.

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Features & Specifications

Mention the words "CPU cooler," and many readers will conjure an image of some form of copper or aluminum heatsink base, slotted fins, and a fan atop the unit. Before the dawn of all-in-one (AIO) closed-loop liquid cooling, the standard choice for processor cooling was the traditional air cooler. Now, CPU coolers compete against a legion of available cooling options for performance, visual flair, and the almighty dollar while appealing to every facet of customization or niche market.

Specifications

The Scythe Grand Kama Cross 3 is a large, 4-heatpipe cooler incorporating an 11-blade, 140mm fan above what could best be described as a ‘butterfly’ layout of fin arrays, rather than the traditional vertical tower layout. The cooler base is a solid piece of 1/8" (3.5mm) thick nickel-plated polished material (presumably copper), upon which the four heat pipes sit. This means Scythe has designed the Grand Kama Cross 3 not as a direct heat pipe cooler, as we've seen with many other solutions. Rather, it relies upon thermal conduction to move heat off the CPU's integrated heat spreader surface through a solid slab of metal and then into the heat pipes.

The base is highly polished and arrives devoid of any factory-applied thermal compound, although Scythe does include a small packet of paste.

The collection of four heat pipes runs across the breadth of the base, but they don't have full contact with the mirror-finished base; you can easily see gaps around the heat pipes, because they aren't fully integrated into the base of the cooler or otherwise filled with solder. The heat pipes arc upward and then inward at close to a 45 degree angle, therefore crossing the opposing arms of each pipe before entering into the fin banks on either side, beneath the cooling fan.

The top of the fins and heat pipes terminate under the semi-gloss black-metal fan mount that also acts, somewhat, as a shroud. Airflow for the cooler is focused down and through the fins. One particularly curious thing is how the heat pipes are wrinkled and distressed, presumably from the process and stresses of bending them into the crossing shape for the cooler. Whether or not these imperfections impact cooling is unknown.

Although the shape and size of the cooler is unique and quite large, it does sit centered directly above the CPU socket without any noticeable offset. While installation for most air coolers is somewhat similar from cooler to cooler on any given Intel or AMD socket, the Scythe Grand Kama Cross 3 does require a bit of a balancing act and a special, long screwdriver (included) to affix the final cooler screws securely. The best method of reaching these screws is going directly down and through the fan and the cooler itself, but since the screwdriver is slightly magnetized, it allows for the screw to be placed on the Phillips’ end and guided into place from above, provided your aim is true.

This final mechanical step does take a bit of finesse and almost requires an extra set of hands in order to steady the cooler and align these screws until both sides have their threads started in the mount. It took us a couple of attempts to get this just right and successfully mount the cooler. Once completed, the Scythe Grand Kama Cross 3 covers a great deal of real estate over the processor, system memory, and motherboard power delivery. 

The cooler’s fin banks come close to the top-most PCI-e slot, but do not inhibit its use, provided a graphics card or other component does not have a large back plate or any raised connectors.

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Comparison Coolers, Testing Results & Conclusion

We use test data and hardware from previous CPU cooler reviews to provide a set of standardized results to be used for comparison. We will be looking at data from be quiet! Dark Rock Pro 3, Noctua NH-U14S, and Noctua NH-D15 with data from Scythe Grand Kama Cross 3 in our results. Our testing involves two hour runs of Prime 95 AVX using Small FTTs on our 4.2 GHz Intel Core i7-5930 hex-core CPU at both full and half fan speed.

The Prime95 AVX testing at full and half fan speeds shows that the Scythe Grand Kama Cross 3 lags a bit behind the other coolers in both regards, including cooling of surrounding motherboard components. However, we cannot credit the increased cooling capability to direct-contact heat pipes, because none of the coolers in our testing comparison uses this design. All use a form of CPU contact base that offsets the heat pipes, so while this similarity removes one variable, it provides some insight into some of the differences, as well.

We also find that the Scythe Grand Kama Cross 3 peaks a bit higher on our sound scale than those in our comparison set. Although we should note that the bar graph does seem to indicate a substantial difference in sound level being registered, the reality is that the 30 decibels is often described as a silent library, while 40 decibels is similar to that of a very quiet room.

We can now see how the thermal performance against noise levels plays out for the Scythe Grand Kama Cross 3. Both the be quiet! Dark Rock Pro 3 and the Noctua NH-U14S go neck and neck here, while the Noctua NH-D15 hovers at a distant third.

Although we have seen that the Scythe Grand Kama Cross 3 does not perform nearly as well in the thermal load and noise level testing, when you factor in the significantly lower cost of the cooler, it rebounds to a very respectable place on the performance vs. value comparison chart. This offers a more comprehensive cross-section for system builders on a smaller budget.

The Scythe Grand Kama Cross 3 puts up some respectable figures against heavyweights in the large air cooler class, and for significantly less money. At full speed, it is nipping at the heels of the more expensive Noctua NH-U14S and be quiet! Dark Rock Pro 3. And it costs almost half as much. When we consider cooler noise levels, we’re still in the realm of registering just over a whisper for this budget performance. With an MSRP right around $45 at time of writing, the Scythe Grand Kama Cross 3 is a large, quiet air cooler that gets close to premium air cooler performance for a fraction of the cost.

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Features & Specifications

The Scythe Mugen 5 Rev.B (SCMG-5100) adds AM4 support to a previous cooler model that we haven't tested yet (SCMG-5000). Both versions use a single large heatsink and a single 120mm low-speed fan to improve cooling and lower noise.

Specifications

Features

Within the box, you’ll find the heatsink, a 120mm stock fan, mounting brackets for the cooler, the owner’s manual, a long screwdriver, and thermal paste. Bracket options include every standard available from Intel and AMD motherboards, including the AM4 socket. The Mugen 5 also comes with a manufacturer’s two-year warranty.

The cooling pipes are plated the same color as the rest of the cooler, giving it a uniform silver finish across the surface. The fan is a matte black color. Those concerned with color coordination should find it a safe bet to go with many different build themes. The CPU contact surface is smooth and reflective. There’s plenty of room for airflow in between the heatsink's largely spaced out slabs. Six heat pipes support the CPU contact plate.

Brackets are easy to install with a screwdriver, and they are sturdy. An included plate that fits behind the socket of LGA 1150 through 1366 motherboards is not necessary in our LGA 2011-v3 system. The screwdriver is extra long to reach the spring-loaded screws at the base of the heatsink, securing it to these brackets. Fitting the fan to the heatsink requires some hand coordination, as the kit includes skinny metal clips to secure the fan. But the fit is secure, even with the small clips.

With the fan installed, it’s important to be aware of the cooler's 0.36” offset. If this offset interferes with some of the motherboard connections, the heatsink can be installed in the other direction. We didn’t experience this issue, however.

There's a small graphic logo featured on top of the heatsink, which would look good installed in either direction. The studs coming out of the heatsink add a nice aesthetic touch.

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Test Methods, Results & Conclusion

Comparison Products

Unparalleled in size when compared to other recently tested single-fan coolers, today we compare it to the thickest coolers to use the same fan size.

The hardware setup for the cooler reviews remains consistent. It includes a Core i7-5930K with a slight overclock using a moderate voltage level inside a well-ventilated Corsair 760T case. The motherboard is set to a 115°C throttle point, and temperatures in the chart are above ambient (the thermal reading, minus the room temperature).

Test Results

Temperatures reported are quite average. This is adequate cooling for the price range.

The Scythe Mugen 5 Rev.B stock fan runs at very low RPMs.

You can see how the low RPM fans keep the noise at a very good (quiet) level, especially in comparison to similarly marketed options.

The Mugen 5 Rev.B is highly efficient, and at this price point it’s very attractive for builders seeking a silent solution.

This representation of the Mugen 5 Rev.B’s value tells us one thing: your product choice depends on what you’re after in this price point. Do you need the extra cooling offered from something like the DeepCool Gammaxx 400 or the Cooler Master MasterAir Pro 4? Or are you looking for the quietest option for your dollar? The Mugen 5 Rev.B performs on average for cooling. It's difficult to get the best of both worlds, and at this price point that’s even less likely. If you want it all, you'll have to spend more.

Overall, we were impressed with the strengths of this cooler, however. It is surprisingly quiet, has moderately good cooling potential, sells at an attractive pricing, and even possesses nice aesthetic flair, making it a great value.

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Introducing The Fuma SCFM-1000

Specifications

Scythe, which opened its doors in 2002, has been producing high-end CPU coolers longer than some of us have been building PCs. The company was a premium brand before other premium brands began charging an even higher price premium, and its Fuma SCFM-1000 is barely more than half the price of several similarly-designed competitors.

Launched last year, the Fuma SCFM uses the traditional pairing of a copper base and heat pipes to aluminum fins, deviating slightly from the norm in the polishing of its top fins and the dimpling of its center fins. It fits the rectangular mounting pattern of traditional AMD motherboards (pre-Ryzen), in addition to all of Intel’s square ILM LGA’s. Oh, and the dimples make air vortices that should remove heat more efficiently.

The copper base appears to be slightly convex, and is plated (along with the heat pipes) in a protective metal that is likely nickel (though the color is closer to chrome). Like the top fins, the bottom fins also use a special design that obscures the dimpling of the center fins.

While most installations require the use of an included support plate, which must be placed behind the motherboard and attached from the top using standoffs and insulating washers, LGA 2011 (v3) users can instead install a special set of standoffs that screw into the motherboard’s integrated socket support. Two cross brackets are then installed, top and bottom for front-to back (or back-to-front) flow, and these brackets must be rotated 180° to fit legacy AMD motherboards. One of the two cross brackets is installed in the photo below.

After removing the protective sticker from the base and applying thermal compound, a third cross-bracket pinches that base of the Fuma SCFM-1000 tightly against the top of the CPU. The screws that join these brackets are threaded only around half-way to prevent over-tightening, yet the installation guide still warns against over-tightening.

There are two challenges builders must face: the heat sink has only 1.3” of clearance between the bottom fins and any surrounding components; and the fans are held on by clips that stick out the front. While additional memory clearance can be achieved by moving the front fan up the heat sink, installing the center fan requires the builder to wiggle the top wire clips past protruding fins of the forward sink while using the clips’ thumb holds to maneuver it past the rear sink.

Test System Components

We continue using our 2015 Reference PC minus its open test bed (and obviously, the reference cooler) to test the Fuma SCFM-1000 in a closed system. The Core i7-5930K is overclocked to a fixed 4.2GHz core frequency at 1.20V core voltage.

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Test Results And Final Analysis

We haven't tested a dual-120mm double-tower cooler in a while, and were forced to find the closest approximations from more recent tests. These include the be quiet! Dark Rock Pro 3 with 120mm front and 135mm center fans, Deepcool (Gamer Storm) Assassin II with 120mm front and 140mm center fans, and the Cryorig R1 Ultimate with dual 140mm fans.

The three comparison coolers are slightly larger than the SCFM-1000, and charts are arranged in order of fan size. Given those differences, it’s easy to see why the temperatures are coolest at the bottom. Still, with full-fan-speed temperatures matching the two most closely-sized competitors, the SCFM-1000 remains competitive.

Part of the reason why the SCFM-1000’s half-fan temperatures were a little higher is that setting its fans to a 50% PWM duty cycle produced an actual speed of somewhat less than half its full speed. On the other hand, that’s certain to benefit Scythe in the noise measurements.

Results below 20db are also below the validated range of my meter, so that even while we know that the SCFM-1000 made slightly more noise than the Dark Rock Pro 3 at the motherboard’s 50% fan setting, questions remain as to whether the noise level was a full 19db. My guess would be a little lower. Regardless, we can call any of these coolers virtually silent once they’re installed in a case.

The larger CPU coolers are all capable of producing a better cooling-to-noise ratio than the SCFM-1000, but they also cost a bit more. Anyone seeking value must decide which device is cool enough, or quiet enough, for their application.

When I said that competing coolers cost a bit more than the SCFM-1000, I meant 50-100% more. That’s going to be a big “ouch” for value seekers.

I also mentioned that the SCFM-1000 is slightly smaller than its competitors, but what does that imply regarding installation? It means that the SCFM-1000 is short enough to fit the recently reviewed Lian Li PC-O11, whereas the others will not. This photo shows why.

I don’t give out many Editor Recommended awards in CPU cooling, because I feel that most enthusiast market CPU coolers are overpriced. Scythe proved to be the fairly priced exception, with its sub-$50 cooler producing an excellent range of cooling at moderate to ultra-low noise levels. Builders who can tolerate the frustration of installing a center fan as clip wires continuously snag the ends of the cooling fins will be very glad they had the patience for the process after reviewing the bill.

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The Kozuti is a fresh approach to the miniature cooler concept. Scythe puts an 11mm-thick 8cm fan under its heat sink fins, which sucks air through.

The sink is very thin at its sides and thicker in the middle. Three 6mm heat pipes lead from both ends of the base plate to the array of fins. That means each heat pipe is approximately twice as long as the pipes found on Raijintek's Zelos. Can the tiny fan you get with Scythe's Kozuti maintain ample cooling performance?

The heat sink also sports a more elaborately engineered base plate than the Zelos. Its heat pipes don’t touch the CPU’s spreader directly, but are routed into the base plate and soldered to it. The base plate's bottom is polished to a mirror finish.

In order for the small fan to generate sufficient air flow, it spins at up to 3300RPM. However, a wide range of rotational speeds allows it to throttle back to 970RPM at idle.

Installation And Compatibility

The Kozuti offers a wide range of processor interface options, supporting Intel's LGA 115x, 1366 and 775, plus AMD's most recent sockets. But there's no such thing as a free lunch; the cost for this flexibility is a more complicated installation. Then again, how difficult could it really be to get a small heat sink installed on a compact motherboard?

First, you need to screw interface-specific mounting brackets to the cooler.

Next, turn the cooler upside down and lower the mainboard onto it.

From there, the screws can be inserted and tightened.

Scythe includes two sets of rubber washers, one for AMD motherboards and one for Intel-based platforms. You can also use the spare set of washers on the front of the motherboard to prevent the screws from falling out before they're tightened. During installation, it is not necessary to remove the fan.

Scythe's Kozuti is the only thermal solution that can be installed in four different orientations, even on AMD motherboards.

Benchmark Results

Conclusion

That's good news, then, for Scythe's Kozuti, the top performer among the low-profile coolers. And at 1.6” tall, it stays clear of our 2" threshold.

Although the Kozuti achieves solid performance at the cost of high fan speeds and corresponding noise levels, it can also run very quietly at idle thanks to a wide RPM range. At a price just over $50 on Amazon, you also get the broadest processor interface flexibility in the test field, though you're also forced to tolerate a complicated installation procedure.

The build quality is impressive. However, we'd like to see a bracket for attaching a 12cm fan come bundled. A fan of that size could sit on top of this heat sink and take its cooling performance to the next level, assuming you have enough space in your case.

Scythe has unleashed its new Mugen MAX CPU cooler into the marketplace, which despite being a very big cooler, comes with a rather attractive price. This cooler comes with a number of changes over the older Mugen coolers, making it just a little better than before.

This is a tower-cooler. Airflow is provided by one included 140 mm fan, though a second one can be mounted to it fairly easily by using the included brackets. The included fan is a PWM supporting fan which will spin at speeds between 500 RPM and 1300 RPM. Noise levels range from a quiet 13 dBA to a noisier 30.7 dBA, while airflow will range from 37.37 CFM to 97.18 CFM. The heatsink is a large tower which is built using a many aluminum fins. The weight is approximately 720 grams without a fan installed.

CPU socket support isn't something you'll have to worry about, as it can be mounted on most modern CPU sockets. These include the AMD FM2+ and AM3+ sockets, as well as the Intel LGA1150 and the LGA2011 sockets.

Pricing for Europe is predicted to be set at €36 ex. VAT, so we expect this one to cost just shy of $50 in the U.S. Pretty reasonable for a large tower CPU cooler.

Follow Niels Broekhuijsen @NBroekhuijsen. Follow us @tomshardware, on Facebook and on Google+.

Scythe has announced yet another new fan controller – the Kaze Master Flat II. This fan controller is built with a simple front panel design with quite potent hardware behind it to back it up. It fits in a standard 5.25" bay.

The unit has four channels, each of which can drive up to 3 amps. At 12 V this equates to 36 W per channel. The channels' output voltage can be adjusted to run as low as 3.7 V, and both 3-pin and 4-pin PWM fans can be connected. When using PWM fans though, the unit will still only control them through voltage adjustments, as the unit does not have PWM support.

The unit also has four temperature sensors set to measure temperatures up to 100 C. Users can also set alarms to go off at 50, 60, 70, 80, or 90 degrees C, depending on what was selected.

On the display, users will see RPM measurements as well as temperature measurements in either C or F.

Pricing for the unit is set at €26 ex. VAT, which translates to about $36.

Follow Niels Broekhuijsen @NBroekhuijsen. Follow us @tomshardware, on Facebook and on Google+.

Scythe has revealed a new CPU cooler: the Tatsumi 1000B. This is a simple entry-level CPU cooler that should be widely compatible.

The cooler is built using an aluminum fin stack to which heat is fed through three 6 mm thick copper heat pipes. Heat gets transferred to the heat pipes through the use of a nickel-plated copper base.

The fan on the unit is a 92 mm fan which can rotate at speeds of up to 2500 RPM, though because it is PWM controlled will be able to rotate at speeds as low as about 300 RPM for when the system is doing some extra-heavy nothing. At full speed the fan will push up to 55.55 CFM of air while making about 31 dBA of noise.

Pricing for the unit is set at 3280 Yen (ex. VAT), which translates to about $32 USD. Shipping starts on May 2 with no word on U.S. availability just yet.

Scythe has revealed its new Iori compact CPU cooler. The unit features a top-down flow design, and is supposed to be used on Mini-ITX and Micro-ATX systems where space is sometimes a scarce commodity.

Heat is taken from the CPU surface by means of a nickel-plated contact block which transfers the heat to three 6 mm thick copper heat pipes. In turn, the heat is brought into an aluminum fin array, from which the heat is dissipated using a 100 mm fan. The fan is PWM capable and can spin at speeds ranging from 300 RPM to 1800 RPM. As such, noise levels can range from an inaudible 4.5 dBA up to a moderate 26.7 dBA.

The entire structure weighs 400 grams and measures 107 x 92 x 136 mm. This compact format allowed Scythe to employ a push-pin mounting system, making mounting the cooler to a motherboard a snap.

Compatibility is stated for most modern CPU sockets, including AMD's AM3+ and FM2+ sockets as well as Intel's LGA115X sockets. European availability is immediate with ex-VAT pricing of €24.50. No word on U.S. pricing yet, but we can expect it to be about $25, or not far from there.

Scythe has initiated the sale of its Lori mid-range CPU cooler.

The cooler is built using a medium sized, downward facing aluminum fin stack, to which heat is fed through three copper heat pipes. On top of the unit users will find a 100 mm fan that can spin up to 1800 RPM, but keep the noise level below 26.7 dBA.

The cooler will be compatible with pretty much any modern-day CPU socket you throw it at, including AMD's AM3+, FM2, as well as Intel's LGA1150 and LGA2011 sockets. It'll weigh only 400 grams.

The cooler has an MSRP of $35 and should either already be in stores or will be arriving soon.

To mark the company's 10th anniversary, Scythe has launched a special edition of its well-received Ashura CPU cooler that was first introduced in January 2013 and was included in our review of Nine Big Air Coolers for Intel's Haswell CPUs. The Ashura Shadow features a striking anodized black aluminum finish and a number of unspecified optimizations to the heatsink, connecting heat pipes and solid copper baseplates that offer better thermal performance.

As with the standard edition, the cooler features Sycthe's "screw-based mounting system" that offers fast and convenient mounting for most recent AMD and Intel CPU sockets and is bundled with a 140 mm Glide Stream PWM cooling fan which is capable of operating between 500 and 1300 RPM and moving up to 97.18 CFM of air.

The Scythe Ashura Shadow CPU cooler (SCASR-1000SE) retails for €39.50 ($53.74) and will be limited to just 3,000 units worldwide.

Eight Low-Profile Heat Sinks For Your Compact PC

Compact enthusiast-oriented PCs are becoming increasingly popular as hardware vendors improve the efficiency of their components alongside raw performance. In the last year, we've covered complete mini-ITX systems, low-profile memory kits, and small enclosures. We even based an entire System Builder Marathon on the mini-ITX form factor.

One thing we found during that exercise was that it's difficult to match the dimensions of boutique-built boxes with high-end hardware, if only because there aren't many enclosures optimized for tiny spaces and big specs. Always eager to make bold statements of frugality, I came upon ASRock’s M8 mini barebones system, to which I added a number fairly potent parts. I then ran smack up against the reason that Chris paid big bucks for his Tiki: ASRock’s M8 wasn’t designed for high-performance CPU cooling. The best I could do was 4 GHz, and that was only after I reconfigured the barebones machine's intake and exhaust fans, upgraded the CPU cooler, and locked the processor's core voltage at a level below Intel's stock ceiling. Clearly there was room for improvement.

We set our upper limit for cooler size at 4” to cover the largest of slim cases, and eight different heat sink vendors responded with samples. Six of them even fit within the approximate 3” limit of ASRock’s M8. One manufacturer said it thought its submission would qualify, but might not fit our test motherboard (even though we were sure it would). Several others asked us for a few additional millimeters of headroom, though that would have resulted in a vicious cycle. It was important to us that we keep this a comparison of truly low-profile coolers to address the growing compact computing market.

Here are today’s contenders:

Due to distribution issues, the Gabriel CPU cooler’s price is an estimate based on the company’s other products. That doesn’t leave any room for award recognition, but it still lets us get a look at performance in lieu of its final release. Noctua’s NH-L12 is distinct in that it's the largest cooler to qualify for our story.

Thermalright’s special-edition AXP-200R is similarly estimated to cost slightly more than the AXP-200. Both coolers are identical apart from fan color, though we aren't worried about value judgements on a product that sells for at least $64. On the other hand, exceptional performance could open the door to Tom's Hardware Elite recognition, regardless of price.

Designed to support two fans in a push-pull configuration, SilverStone’s NT06-Pro includes only one. The firm instructs users of low-profile cases to mount the fan below its radiator, so that’s how we're testing it. It might even squeeze into ASRock’s M8 in this configuration, though the side panel would probably block airflow through its fins.

Gamer Storm Gabriel

Best of luck getting your hands on the latest heat sinks from DeepCool Industries. Most of the company's products are re-branded as Logisys by online vendors sourcing them from that importer. The sub-brand Gamer Storm is rarely used in price engines. And sometimes even the product name doesn’t appear. For a while, the firm’s older Gamer Storm Assassin was simply branded as Logisys MC8000 in the U.S.

To compound our issues finding this piece of hardware online, our Gabriel sample doesn’t even have a part number. Presumably, that'll get assigned to the retail packaging, which isn't finished yet.

Apart from issues with availability and naming, DeepCool presents a fairly thoughtful and well-executed design in its Gamer Storm Gabriel. We find a copper base with four heat pipes connecting aluminum fins, all protected under a nickel-plated finish.

Our sample came with LGA 115x (1150, 1155, 1156) brackets for Intel’s three most recent generations of mainstream processors, and AMD brackets that fit all four-hole rectangular mounting patterns. We wouldn’t expect a cooler this small to be marketed towards giant LGA 2011 processors, so we’re not disappointed.

Gabriel Installation

The Gamer Storm Gabriel by DeepCool (and likely to be imported by Logisys) doesn’t weigh much, so it doesn’t need much contact pressure. Rather than add a socket support plate, the firm simply attaches this cooler using screws and insulating washers. These protrude through the back of the motherboard to connect standoffs and mounting brackets seen on the previous page.

With 1.1” of clearance for voltage regulators and memory, and around half an inch of offset in two directions, the Gabriel CPU cooler can be rotated to fit most motherboards. Buyers should still measure their boards to assuage any fitment concerns, though.

A low-profile fan clips on to finish the installation, bringing total mounting height to a mere 2.4”. This one would have definitely fit into our ASRock M8 build, though its clips wouldn’t have supported our thicker fan upgrade.

Since the Gabriel is offset in two directions, it shouldn’t be too difficult for most users to find a mounting orientation that supports a second pair of tall DIMMs. If that’s not an option, we’d suggest low-profile memory.

Noctua NH-L12

Designed for semi-slim cases, Noctua’s NH-L12 could become a truly slim cooler by removing its 120 mm top fan. A second option for reduced profile would be to replace its 92 mm bottom fan with the top fan, though doing so would significantly diminish motherboard component and DRAM clearance. Noctua only recommends the first two options (both fans or one 92 mm fan).

In addition to mounting hardware, the NH-L12 includes a fan splitter and two speed-reducing resistor wires. While we prefer to let our motherboards manage fan speed, we’ll entertain ourselves with both high-speed and low-speed mode tests.

Noctua machines its copper base plate to an ultra-fine surface before plating the entire NH-L12 in corrosion-resistant nickel. Spring-loaded cap nuts with Phillips-head tops are also factory installed.

Some processor interfaces have built-in support plates; others don’t. Noctua still supports LGA 775-based motherboards by extending foam support material across most of its cross bracket, and it supports newer Intel platforms by making that center section removable. AMD and LGA 2011 owners have the benefit of direct-mounting Noctua’s brackets to the motherboard's original support mechanisms.

NH-L12 Installation

Noctua’s LGA plate is slotted for Intel’s three consumer-oriented mounting patterns, using push-through bolts as stands for top-side hardware. Note that the LGA plate is notched in two places to clear the screws of Intel’s original support mechanism.

Another option would have been to install the cooler without a plate. To circumvent clearance problems seen in our System Builder Marathon last June, Noctua also includes a special screw and nut set to install the NH-L12 in the same fashion shown in the Gamer Storm Gabriel installation.

Regardless of whether you’re using bolts or screws, the next step is to install black plastic spacers and cross braces.

An exceptional 1.6” of clearence is reduced by around half under the 1”-thick inset bottom fan, though the fan can be slid a little to make more room at one end. Half an inch of offset also allows the cooler to be rotated to clear specific components.

Too thick for our M8 build, we might have retested the NH-L12 without the top fan, except that it’s already being retested with its included speed-reducing resistor wires.

Scythe Big Shuriken 2 Revision B

Is the name “Big Shuriken” a contradiction? While the word may refer to a small bladed weapon, anything smaller than Scythe’s low-profile cooler might have been more-appropriately named Shaken. Then again, the Shuriken is larger than the stock Intel LGA 1150 cooler.

The Big Shuriken 2 Rev. B is even large enough to hold a 120 mm fan above its ultra-thin cooling fins, relying on five double-sided heat pipes to support high thermal loads, purportedly including those of LGA 2011 processors. The installation kit even includes custom screws to utilize LGA 2011’s integral mounting bracket, in addition to Intel’s other consumer-oriented interfaces and the rectangular screw pattern of AMD’s recent mounting brackets.

Scythe puts anti-corrosion nickel plating on its semi-polished copper base, but leaves its copper pipes au naturel.

Threaded collars screw into the Big Shuriken 2 Rev. B’s mounting brackets to allow installation from behind the motherboard on any compatible socket except LGA 2011. Those installations instead require that bolts be secured using a wrench from the side.

Big Shuriken 2 Revision B Installation

Scythe’s socket support plate has holes in every direction to fit around the mounting screws of Intel’s integrated solution. Tabs on two sides of the bracket also support AMD installations.

In spite of its low 2.3” mounting height, the Big Shuriken 2 Rev. B offers 1.6” of clearance for DIMMs and motherboard components. It gets that space through the combination of a thin radiator and slim fan.

The Big Shuriken 2 Rev. B has a snug profile, but still clears the medium-height heat spreaders of our memory modules.

SilenX EFZ-100HA2

Does anyone remember flower-style coolers? Few of us would claim to be old enough, though some may have forgotten about this design. Fortunately, it still has some merit.

Low manufacturing cost of this sheet-aluminum design is probably the biggest benefit of SilenX’s EFZ-100HA2. After all, easier manufacturing leads to a supremely-attractive $15 retail price.

Smashing those fins tightly together allows SilenX to machine a smooth surface upon the EFZ-100HA2’s base. Aluminum rivets hold it all together.

Designed to clip onto AMD’s Socket 462, the manufacturer must have been thrilled when AMD decided to keep those clips for generation-after-generation of AM and FM interfaces. SilenX adds an adapter bracket for LGA 775 and LGA 1156, and must have been similarly thrilled when Intel decided to keep the 1156 hole spacing for LGA 1155 and 1150. Locking pins sit in oval holes to allow the builder to select between LGA 775 and LGA 115x compatibility.

EFZ-100HA2 Installation

White split pins on the Intel LGA adapter fit into mounting holes first, followed by black plastic tacs. This is the only cooler in today’s round-up that doesn’t require motherboard removal.

A look under the motherboard shows how the black plastic tacs wedge between the ears of those split pins to look the adapter in place.

The EFZ-100HA2 now clips onto the Intel LGA adapter in AMD style, using its original Socket 462 spring clip.

Because its fins are narrow and tapered, the EFZ-100HA2 has the best component clearance of any cooler in today’s test. On the other hand, that taper makes it hard for us to define its clearance in either inches or millimeters.

SilenX calls this a 100 mm fan, but its blades are an exact match to several 92 mm x 25 mm fans that we compared. Metric fan sizes are based on frame size, and the blade diameter of this frame-less fan is around 86 mm.

SilverStone Nitrogon NT06-Pro

Forget the word Nitrogon in your product searches, as most vendors refer to SilverStone’s latest low-profile cooler simply as the NT06-Pro. Designed to hold two fans, the single included fan complies with the low-profile requirements of many builders. Today, that includes us.

An intricate mounting kit includes a separate screw set for LGA 2011, cross brackets for Intel and AMD sockets, extension screws and spacers, a socket support plate for all compatible sockets except LGA 2011, and a spacer for boards that don’t have a built-in support plate (LGA 775).

SilverStone sands the NT06-Pro’s copper base to an ultra-smooth finish before plating the entire cooler in corrosion-resistant nickel. Short fins above the base provide access for mounting screws.

The NT06-Pro uses a variant of carriage-bolt design to prevent turning of the mounting screws in its base plate. The plate has holes for LGA 775, 1150/1155/1156, 1366, and the four-hole rectangular pattern used to hold AMD’s specified clip brackets.

Nitrogon NT06-Pro Installation

Carriage-style bolts extend from the included support bracket through the motherboard, and are topped with plastic spacers, cross brackets, and nuts. LGA 2011 mounting instead uses a special set of screws to hold the same cross brackets and nuts.

With its fan out of the way, we can see how the NT06-Pro’s top mounting bracket connects to its cross brackets using spring-loaded cap nuts. Phillips head indentations allow cap nuts to be tightened through heat sink access holes using a screwdriver.

Exactly 1.2” of motherboard component and DIMM clearance remains after installing the included 120 mm x 20 mm fan. SilverStone recommends both updraft and downdraft configurations, so we tested it both ways.

The bottom of the fan sits next to our medium-height modules, preventing the installation of a second set. Memory upgrade options include using shorter modules or rotating the sink away from memory.

Thermalright AXP-200 And AXP-200R

A red-and-black fan color scheme differentiates Thermalright’s AXP-200R from its more pedestrian sibling, and the firm even rates both product's fans at the same speed. Since they employ the same fan motor and design, readers should be confident of identical performance. The AXP-200 sells for $64-$80, and we estimate the special edition version in our lab is at the upper end of that range.

The AXP-200R includes a multi-sized fan adapter plate in addition to its Intel LGA and AMD four-hole mounting kits. Users can substitute the original slim fan for full-sized fans up to 140 mm, as well as Thermalright’s own 150 mm x 26.5 mm unit.

Thermalright polishes its CPU interface better than most competitors, though this does appear to affect flatness slightly near its edge. Nickel plating prevents surface oxidation.

The AXP-200's support plate is drilled for all consumer-oriented Intel and AMD processors, replacing manufacturer-supplied brackets for AMD coolers as far back as Socket 462. Extra holes near its center fit around the screws of Intel’s original support plates, and LGA 2011 users can instead use their original threaded mounts with a set of supplied standoffs.

AXP-200R Installation

Thermalright adds a support ring around the socket, and uses yet another bracket to push its cooler base towards the CPU. Divots on the edge of the ring align to AMD’s bracket hole spacing, and slots in the ring’s corners fit Intel’s LGA interfaces.

Shown on the previous page, carriage-style bolts attached to a socket support plate slide through motherboard holes to be topped with threaded spacers. Insulating washers prevent motherboard damage, and the assembly is topped with the ring-shaped cooler bracket and screws.

LGA 2011 installations instead use a set of supplied standoffs to attach the ring bracket over and around the socket.

Thermalrights AXP-200R does not support under-sink fan installation, but does clear DIMMs and motherboard components up to 1.4” tall. Missing fins at one end of the sink provide screwdriver access to install the final hold-down bracket.

Though its color scheme is ROG-specific, the AXP-200R’s red and black fan looks great with the red memory and black PCB of this non-ROG platform.

Xigmatek Janus

Initially available to U.S. customers from a single exporter in Singapore, Xigmatek’s Janus now sells for $40. A quick comparison of current Xigmatek products leads us to believe the eventual price will be around $30.

That price range gets buyers a dual-fan sink and two coolers: 120 mm x 15 mm on top and 80 mm x 10 mm on the bottom. Two sets of brackets fit all consumer-oriented Intel and AMD sockets from LGA 775 and Socket AM2 forward. Bolt-through installation supports all of those sockets except LGA 2011, for which Xigmatek includes a special set of standoffs.

The Janus we received was polished only half-way, showing its original machining grooves across most of its surface. These grooves are shallow and should fill nicely with paste to provide a fairly good thermal interface, and are protected from oxidation with nickel plating.

Xigmatek's submission uses a carriage-bolt design variation with threaded standoffs and insulating washers to fit onto the board from above. Most installations require users to reach around the back of the board to secure the cooler with nuts, but LGA 2011 instead requires that you reach between the motherboard and cooler with a supplied wrench.

Janus Installation

Screws from the assembled Janus cooler and bracket package stick through the motherboard and are secured with nuts. A set of insulating washers protects the board’s surface. If you own an AMD processor, you'll need to remove your board's cooler retention mechanism to accomplish this task.

The Janus provides 1.2” of clearance for DIMMs and motherboard devices, and is offset by 0.6” towards the side shown so that it can be rotated to clear taller objects. The bottom 80 mm fan needs additional space above the socket, but can be removed if necessary.

At 2.5” tall including its top 120 mm fan, the Janus is exactly the design we expected to represent the low-profile performance market. The fan even lights up for users of windowed cases such as ASRock’s M8.

If you need a second set of DIMMs to use with the Janus, you'll either want lower-profile memory or to rotate the cooler away from the memory slots.

Zalman CNPS8900 Quiet

An advancement of the aforementioned flower-style coolers, Zalman’s CNPS8900 Quiet wraps two heat pipes around copper fins to improve thermal conductivity.

A universal socket support plate uses the LGA 1150/1155/1156 and 1366 plate as a spacer, and includes a piece of plastic to serve the same purpose on other platforms (Intel LGA 775, AMD AM and FM interfaces).

Zalman’s CNPS8900 Quiet is the only cooler in today’s comparison to use a direct-contact heat pipe design. Once hailed by many firms (and several reviewers) as a giant step forward in cooler base design, its proven benefits are typically reduced material cost for the manufacturer and weight. After smashing the contact surface flat, Zalman sands it smooth.

Zalman uses shoulder screws to keep its CNPS8900 Quiet mounting brackets away from the motherboard’s surface, but doesn’t include screws for LGA 2011. Unlike several competitors, the company doesn’t appear eager to push undersized cooling onto oversized processors, and we can understand that sentiment.

CNPS8900 Quiet Installation

T-nuts are placed into support plate mounting holes that correspond to a motherboard’s mounting pattern, and are held in place with plastic retainers. These are barely long enough to reach the top of the board using Intel’s original socket support plate as a spacer.

Shoulder screws secure top brackets to the under-motherboard T-nuts. The CNPS8900 Quiet is too large to allow vertical access to the #2 Phillips heads of these screws, and we found that a #1 screwdriver could more easily be angled into place.

Like the traditional flower-style cooler that’s also in today’s comparison, the CNPS8900 Quiet is small enough to clear nearly any motherboard component and angled in a way that complicates precise clearance measurements.

With only 1.3” of space under the edge, CNPS8900 Quiet users who need to add more memory should probably choose low-profile DIMMs.

Test Settings And Methodology

One point of testing all these coolers is to find one that really allows overclocking in tight spaces. The problem is that cramped PCs are usually warm without even beginning to overclock. Given the problems of small enclosures and the lack of custom-fit solutions (such as the one found in my boss’ Tiki), I picked the O/C settings from our ASRock M8 review.

Another market for compact cooling is found in home theater systems, where stock cooling solutions might be too noisy. Thus, acoustics are an important consideration in today’s analysis.

The cooling capacity versus noise debate brings up a point made by one of our readers in our recent closed-loop cooling finale. Some products achieve their best cooling-to-noise ratio at a fan speed that’s significantly below maximum. Other coolers behave as if they need more powerful fans to reach their full potential. Readers suggested that we retest everything using a common fan arrangement, but that doesn’t work in a low-profile device comparison where many of the test subjects can’t hold a common fan configuration, or would no longer fit within the low-profile theme using standardized fans.

We don’t like playing favorites, but we also don’t like punishing a company for adding the extra capacity of a 3600 RPM fan when the product operates optimally at 1800 RPM. On the other hand, it would be arbitrary to pick our own fan speed and apply it to all products regardless of design factors.

So, I’ve left it to manufacturers to decide what speed to use. If the product includes a two-speed selector, I test both speeds. If it includes a resistor wire, I’ll use it. If it’s an analog controller, I’ll test the top and bottom speed settings. At this time, I cannot find a fairer method to compare cooling to noise other than to rely on the hardware included with the cooler.

Results: Cooling And Fan Speed

Unable to fit into our ASRock M8 project but still barely qualifying as low-profile, Noctua’s NH-L12 leads the cooling charts. Remember that these tests are based on a low CPU core voltage to compensate for reduced cooler capacity.

SilverStone’s NT06-Pro takes second place in the cooling chart, though it wouldn’t have room for air circulation in the M8 chassis. Thermalright’s 2.8”-tall AXP-200R is the best performer to fit that specific enclosure, followed closely by Scythe’s lower-cost Big Shuriken 2 Rev. B.

Adding the included resistor wires to the NH-L12 lowers fan speed significantly, but with only a minor increase in temperature. Higher overclocks might have changed this scenario, but we’re trying to use settings that all of these coolers can support.

Results: Noise And Acoustic Efficiency

Decibels are on a logarithmic scale, so every ten decibels has twice the apparent audio volume. But air is compressible, so sound sources don’t stack up as neatly. Ten times the source energy is needed to double sound pressure, and a drop of 3 dB is similar to reducing the source energy by half. With that understanding, we were pleased to see a 5 dB drop in the NH-L12’s noise level accompany the installation of its included resistor wires.

Zalman’s CNPS8900 Quiet similarly impresses us by making very little noise at full speed, and a look back at the thermal charts shows that its 51° over ambient result is very close to the low-speed NH-L12’s 49° over ambient.

A temperature reduction of 50% is a cooling improvement of 100%. To rate improved cooling with a higher percentage score, we divided the stock Intel baseline cooler’s temperature by the actual temperature of each competing solution. We then divided each cooler’s actual noise level by the reference cooler’s noise level to put noise on a direct scale, since the higher denominator produces a lower dividend.

The SilenX EFZ-100HA2 had a 10° advantage over the bundled Intel cooler, yet it's noisy enough to finish worse than the stock solution in a cooling-to-noise comparison. Zalman’s CNPS8900 Quiet takes top honors at full speed, while Noctua’s NH-L12 edges it out with the included speed-reducing resistor wires installed.

Cooling Value

Intel’s stock cooler is bundled with retail processors, so we naturally can't use its price as a baseline. We instead used the average of all coolers, and find that the $15 SilenX EFZ-100HA2 wins the cooling-to-price comparison. On the other hand, the cheap cooler runs too hot to satisfy any of our needs.

Priced at only $40, Zalman’s CNPS8900 looks like a great value in a cooler that meets most of our thermal requirements, and its value rating is closely followed by the slightly-warmer Gamer Storm Gabriel and Xigmatek Janus coolers.

Zalman’s CNPS8900 Quiet also has the low fan speed to make it a great overall performer, in the balance of cooling, noise, and price.

The Best Cooler For Compact Systems?

Noctua’s NH-L12 is the top performer in all of today’s tests, though attaining that status in our noise measurements requires installing resistor wires that also raises its temperature to third place. It's also the largest cooler in today’s tests, and fits only the most spacious of small enclosures, such as SilverStone's SG08. And we’re sure SilverStone would have something to say about that, following closely behind with its own NT06-Pro.

The rest of the field fits most compact enclosures with heights of less than 3”. The best cooling-to-price ratio among these comes from the SilenX EFZ-100HA2. If this were a comparison of basic replacement parts, SilenX’s low price would make it a top contender. But hot and cheap don't win any favors in the high-end cooling market.

Second in the value charts, Zalman’s CNPS8900 Quiet is best among the sub-3” coolers in our Acoustic Efficiency chart. It also takes second place behind the SilenX EFZ-100HA2 in our cost to benefit analysis. It's barely warmer and barely noisier than Noctua’s much larger NH-L12 in its top-performing low-speed mode, and has the added advantage of fitting most compact enclosures.

Two candidates emerge for our top-honor Elite award, the Zalman CNPS8900 Quiet that fits most "slim" enclosures and Noctua NH-L12 that fits only a few. But there can only be one best. And since one of the two products also qualifies for a value award, I’m bypassing the debate between performance superiority and enclosure compatibility.

The CNPS8900 Quiet combines good cooling performance, low noise, broad case compatibility, and a moderate price to make it the smartest choice for the majority of compact system builders.

39 Thermal Compounds Get Benchmarked And Tested

If you missed part one of this series, take a quick second and check out Thermal Paste Comparison, Part One: Applying Grease And More.

We Are Curious About Two Special Compound Categories

After discussing the theory of conventional thermal pastes in part one, I want to go into a little more detail about liquid metal compounds, and also shed some light on thermal adhesives, both in paste and pad form. Thermal pads are used to mount small heat sinks on RAM chips or MOSFETs.

But let’s start with those liquid metal pastes. While their theoretical thermal conductivity sounds impressive, that one attribute is no guarantee of success. During the course of our testing, we'll be experimenting with a long burn-in phase and comparing the liquid metal compound to Gelid's Extreme paste.

Several years ago, Coollaboratory broke new ground in thermal management by introducing the Liquid Pro liquid metal compound. But while the look (and subsequent application) of Liquid Pro reminded us of a mercury thermometer that didn’t survive a fall, its successor, Liquid Ultra, is better, avoiding some of the first effort's weaknesses. Because Liquid Pro could be so problematic, I'm only presenting Liquid Ultra in the tutorial section. Both compounds show up in our performance charts, though.

Box Contents

In the Liquid Ultra box you get the paste itself, a cleaning swab, two brushes, a sponge, and an instruction manual. That's an impressive-sounding list, but it's really just the bare minimum to use the product, sufficient for a single application. If you want to apply Liquid Ultra a second time, you'll find yourself without the alcohol swab. At least a second brush is included. While we appreciate the inclusion of the coarse sponge, it's barely adequate for removing the compound. Of course, there's a separate cleaning kit available for a hefty price.

Enthusiasts may be torn about this product, and yes, there may even be those who are more courageous than I and use it on graphics cards. However, my personal opinion is that a majority of the people who read this tutorial are new to thermal compounds, and I wouldn’t want to encourage them to mess around with this stuff due to the skill it requires. I also want to point out that you'll probably void your CPU's warranty if you do use Liquid Ultra. After removing the last remnants of it, we discovered that all of the markings etched into the head spreader were gone. If you still want to try this product after reading our tutorial, you can probably expect very good cooling performance, assuming nothing goes wrong.

Surface Cleaning and Roughing

The most important prerequisites for using a liquid metal compound are clean heat sink and spreader surfaces. You can buy the aforementioned kit with the three cleaning liquids, or simply snag some isopropyl alcohol at the drug store. However, stay away from acetone and cleaning naphtha. Even denatured alcohol may contain additives that are detrimental to achieving a clean, degreased surface. Finally, make sure you wait until any remnants of the liquid have evaporated!

If the surface is too smooth, the older Liquid Pro and newer Liquid Ultra may only form loose droplets on your CPU. Thus, in contrast to what you would do for regular thermal pastes, you may consider roughing the heat sink and spreader a little bit. Just remember that you only get enough liquid metal for two tries.

Don't overdo this. If you scrub too hard, the innocent-looking sponge can cause deep grooves. Move in small, graceful circles.

Coollaboratory Liquid Ultra: Application

Applying the compound is tricky, which is why we don't really recommend Liquid Pro. Liquid Ultra is a little more like the pastes you're used to, though still a lot "wetter". Its composition is still a point of concern because it corrodes light metals like aluminum and certain alloys. This could have an adverse effect on thermal conductivity, even causing an insulating layer to form. Copper- and nickel-plated surfaces are alright though, as are heat spreaders.

Once you've roughened up your CPU, you can drip Liquid Ultra on it, spreading it around with an enclosed brush. The amount you'll use varies by CPU size, but plan to use about half of the compound on AMD processors and about a third on Intel's. The video shows that you can even add liquid metal while spreading it out. Depending on the mounting pressure of your cooler, you may want to spread the compound more than the video shows. Just be careful; you don't want this corrosive, conductive material to get squeezed out the sides.

The next video illustrates an alternate method that requires less material. What we want to stress, however, is that it is better to put the liquid metal on a CPU away from its processor interface, thus protecting the motherboard from spills. We're putting the chip on our cleaning sponge to make sure none of its pins get bent.

On one hand, the liquid is spread more evenly and less of it is needed. But on the other, more metal balls form. Since they could cause a short circuit, they need to be collected. This method only works when the surface has been roughened, and it yields (marginally) better results.

Coollaboratory Liquid Ultra: Application Problems And Clean-Up

The pictures below are staged. But their purpose is to warn you what might happen if you're not careful, or if you don't pull the CPU from its interface before applying the liquid. Even if you're being meticulous, small droplets will separate and run away. So, keep a thin, clean brush handy to deal with them. Don’t spread them or wipe them away; instead, lift them up!

If you have never experienced the sinking feeling of spotting a liquid metal droplet between CPU pins, look at the bottom picture. However, the tiny droplets at the PCB’s edge may be even worse because they're barely visible to the naked eye.

Cleaning with Chemical Agents and a Wire Brush

It's one thing to apply liquid metal. Removing it is an entirely different ballgame. Even popping off the heat sink can be a challenge. It's very easy to pull an AMD processor right out of its locked socket if you're not extra careful. Make life a little easier by starting the process while the processor is still hot, and detach the heat sink by gently turning it left and right. If you roughed both the heat sink and spreader, you're going to be met with resistance. You might be best off mounting a smooth heat sink on a roughed spreader. This combination seems to come apart most easily.

The cleaning agent from Coollaboratory's cleaning set works, but it won't get everything off. Thus, you still have to use the wire brush. Scrape, apply more solvent, wipe, rinse, and repeat. As you might guess, this takes some time.

In the end, you'll probably wind up with two scratched-up surfaces. Luckily, I bought two closed-loop liquid coolers, allowing him to continue testing conventional pastes with a smooth sink.

Coollaboratory Liquid Ultra: Performance Measurements

If you want to know if this solution is worth its high price, the best we can do is answer with a non-committal maybe. Enthusiasts requiring an expensive, hard-to-apply thermal compound to lower Tcase by 2 or 3 degrees Kelvin (which could mean as much as 5 degrees Tcore) might want to consider their build goals. After running our own tests, we can state with some confidence that the supposed improvements of 5 to 7 Kelvin Tcase are overoptimistic. If you see that big of a gain, it's because you weren't doing something right with the paste you were using before. In order to create a more fair measurement, I compared one of the best conventional pastes, the GC-Extreme from Gelid Solutions, against Liquid Ultra. One-eighth of an ounce of GC-Extreme may be good for five or more applications; Coollaboratory's Liquid Ultra allows three, at most. Even without the expensive add-on cleaning kit, you're still looking at the difference between less than $2 per use and more than $4. You're also looking at five seconds of application time compared to three minutes or so. And we still haven’t taken increased risk into account.

Measurement Results

While Liquid Ultra isn’t compatible with aluminum coolers, we're lucky in that the Core 2 Quad Q6600's old boxed cooler sports a copper slug.

It is amazing how well conventional thermal paste fares compared to liquid metal. A more familiar paste sports a lower difference between burned in versus not burned in, but at a mere 1°C ΔT, the Liquid Ultra certainly proves itself in the same league. Whether we run the interval test or the 24-hour stress test, only Gelid's paste manages to get slightly better as time passes.

Asked whether the 1.5 °C ΔT, which the Liquid Ultra holds over Gelid's GC-Extreme with a closed-loop cooler, or the 2.7 °C  ΔT, which it does in the boxed cooler test, are worth extra effort and cost, my personal answer is no. But of course, some enthusiasts swear by the liquid metal. Most folks don't need the stuff; it's really for the overclockers functioning at the very top of their game.

Thermal Adhesives: Arctic Silver And Akasa

Thermal adhesives binds surfaces together, acting as a thermal compound in the process. They're available both as pastes and in pad form, and may be necessary for mounting small heat sinks on memory packages or voltage regulation circuitry. Obviously, conventional pastes don't work in those cases, since the weight of a heat sink causes them to slide right off.

Adhesive pastes have better thermal properties than pads, but they are accompanied by a significant drawback: once thermal adhesive paste cures, you cannot remove the heat sink from the component without damaging something. We've seen too many pictures from folks who've torn off RAM packages or cracked MOSFETs in half. You can try a trick to avoid this: mix thermal adhesive with regular thermal paste. We'll discuss this shortly.

Paste: Arctic Silver Alumina Thermal Adhesive

Arctic Silver's Alumina is a classic among thermal adhesive pastes, but heed the above warning: once applied your heat sink won't come off again. But a similar non-adhesive version is also available, and you can mix about two parts of the adhesive with one part regular paste to achieve a compromise. Your sink shouldn't be affected by gravity or vibrations, but it should still come off if you need it to. After popping it off, remnants of the adhesive will remain on both surfaces, which you'll want to clean with a sponge.

Adhesive Pad: Akasa AK-TT12-80 Thermal Adhesive Tape

It is easier to use an adhesive pad, if you don't mind the compromise in thermal conductivity. But for making sure that RAM packages and MOSFETs don’t get too hot, pads are typically good enough. If you ever plan to change or remove the heat sinks you're attaching, use an adhesive pad rather than paste.

Pastes: Akasa And Alpenföhn

Akasa 455

Model 455 is basically the entry-level product from Akasa. However, it is quite thick and thus not suitable for beginners. A low price cannot make up for the paste’s difficult application.

Akasa Pro-Grade 460

This paste barely differs from the Akasa 455, described above. It is not any easier to use, and the results we measured are only slightly better. Since it's also more expensive than the 455 paste, its purchase is questionable.

Akasa Pro-Grade+ 5022

This is another product from Akasa that costs more than the one we just looked at. While the performance measurements we generated are again better than the previous two compounds, and it is somewhat softer, this is still a thick paste. Warm it up a bit, though, and it can be applied more easily, yielding very satisfactory results.

EKL Alpenföhn Schneekanone

Schneekanone translates to Snow Cannon, which sounds like a whimsical name promising icy-cold CPUs. While your processor certainly won't hit temperatures that low, this paste's thermal performance is still pretty good. However, its price is too high and it's not very easy to use. While it is more expensive than the classic Arctic MX-2, it isn’t any better. Fortunately, enthusiasts in the U.S. won't need to worry about this, since EKL's Alpenföhn Schneekanone isn't available here. 

Pastes: Arctic And Arctic Silver

Arctic MX-2

This classic compound started the premium paste frenzy. It is still a good entry-level choice, too. Inexpensive and easy to use, its thermal performance is in the upper mid-range. And for what you pay, MX-2 seems like it's meant to keep competitors out of the lucrative thermal paste market.

Arctic MX-4

While MX-4 is more expensive than the MX-2, it surprises us by offering only barely better results. This paste may have its strengths, but it's not your best option for high-power applications like GPUs. It's also tougher than Arctic's MX-2, making it more difficult to use, and less attractive to novices. The thermal performance we recorded puts MX-4 into the upper mid-range, but it also doesn’t stand out from the crowd. Fortunately, at $1.75 per gram, it is one of the least-expensive pastes.

Arctic Silver 5

Buyer beware: The brand Arctic Silver is not the same as Arctic. This is one of the few pastes on the market that still sports silver as an ingredient. However, it shows its age and does not keep up with the best pastes out there today. Based on its performance, it seems overpriced.

Pastes: be quiet!, Corsair, And Dimastech

be quiet! DC 1

As with a number of other manufacturers, be quiet! merely puts its label on an OEM product. That doesn't necessarily indicate poor quality, so long as the OEM maintains certain standards. And as it turns out, the DC 1 is a solid paste for beginners, ending up in the upper mid-range. Its handling is similar to MX-2, while its performance is a notch better. While we like the product’s quality, we cannot say the same about pricing. Amazon currently offers 3 g for close to $10.

be quiet! (Paste Bundled with be quiet! Heat Sinks)

We're curious about the pastes that heat sink vendors bundle with their coolers. Since cost is always a factor when it comes to value-adds, we want to know whether it makes sense to toss the included stuff and buy aftermarket compound instead.

In this case, we are positively surprised by the freebie. It should be good enough to complement be quiet!'s coolers, which employ high mounting pressure. Under those conditions, the paste comes in a mere 0.6 °C higher than the DC 1, mentioned above.

Corsair (Paste Enclosed With Corsair Coolers)

This time we're looking at thermal paste bundled with Corsair's coolers. The be quiet! and Corsair compounds achieve similar results, though Corsair's paste is perhaps slightly thicker. It's still pretty easy to use though, and we like what we see from our thermal performance results. In this case, it probably wouldn't make much sense to toss the tube and spend good money on something else.

Dimastech HTX-EE

This compound is one of the most difficult to use, and you should only apply it after warming to 110 °F or so. Its performance results are barely better than what you get for free with some heat sinks, though, and so we're left a little disappointed. We're not saying that this is a bad paste, but for the money you can find better options. This stuff is so thick that we were afraid our heat sink's screws would strip their threads as we tightened them.

Pastes: Coollaboratory

Coollaboratory Liquid Pro

This is the grandfather of liquid metal compounds, and it still holds the record for thermal conductivity. Unfortunately, it also requires the greatest degree of skill to apply. Only experienced, gutsy professionals should use it, and even then, it's both expensive and difficult to remove. Liquid Pro cannot be used with aluminum heat sinks, but can be used with copper- and nickel-plated ones.

Coollaboratory Liquid Ultra

This latest offering from Coollaboratory is somewhat easier to use than its predecessor. But that only means it's a little easier to apply than Liquid Pro. Its thermal attributes aren't quite as good as a result of the different composition. However, Liquid Ultra is still better than any conventional paste. At the end of the day, you'll have to decide if one or two degrees of improved cooling performance is worth the effort and risk. Again, you cannot use this stuff with aluminum heat sinks, though it is compatible with copper- and nickel-plated ones.

Coollaboratory Liquid MetalPad

While these pads can be handled and cut to size easily, the devil is in the details. During burn-in, you have to ensure that the Tcase temperature reaches at least 140 °F, which equates to a Tcore of about 80 °C (176 °F). Some AMD CPUs throttle back at 140 °F, and even our FX-8350 had a hard time holding the required temperature long enough for a successful burn-in. Older AMD processors may be on the brink of meltdown at 140 °F. Without a successful burn-in, however, this product's thermal conductivity is worse than the cheapest paste. It took disconnecting all of my fans to burn the pads in. Naturally, doing this involves some risk.

Coollaboratory Liquid Cleaning Set

High prices and tedious clean-up make Coollaboratory's products very hard for the newbie to use. They're great for experts who want to leave zero overclocking headroom unexploited, though you'll probably find this cleaning kit necessary.

Pastes: Cooler Master

Cooler Master IC Value V1

This is the least-expensive paste from Cooler Master. It's really easy to use, but doesn’t work any better than the random no-name compounds we've tested. While the price is right, performance leaves a lot to be desired. We can only recommend this product for experiments like this one. Fortunately, it's pretty hard to find in the U.S., so there's a good chance you'll never encounter it.

Cooler Master IC Essential E1

This mid-range compound from Cooler Master is approximately twice as expensive as the entry-level product, but is it twice as effective? Our results put the two pastes fairly close together; only in the GPU-oriented test are the differences substantial. But even so, this paste is fairly average, the amount you get is paltry (a mere 1.5 g), and the cost per gram is substantial. IC Essential E1 isn't a price/performance winner. It is easy to use, though.

Cooler Master Extreme Fusion X1

This is Cooler Master's high-end offering, which sets out to outclass the company's older pastes. It achieves this goal, finishing a close second to Gelid's GC-Extreme. Just be sure to warm up the paste before you use it.

Cooler Master (Paste Bundled With Cooler Master Coolers)

Initially, I suspected that the paste bundled with Cooler Master's heat sinks was the same as be quiet!'s, given almost identical syringes. However, spreading the pastes, which are also the same color, revealed different viscosity. That either means we're dealing with distinct products or the same product from widely varying production lots. Variance does happen, particularly when it comes to inexpensive products.

Be that as it may, Cooler Master's paste sports a higher viscosity and winds up trailing be quiet!'s in the test results. It was still better than some pricey aftermarket compounds, though.

Pastes: Gelid Solutions, Noctua, And Phanteks

Gelid Solutions GC-2

We're going to start with Gelid's most budget-oriented solution. Its thermal results are respectable, landing it in the vicinity of Arctic's MX-2, MX-4, and Arctic Silver 5. But it's also noticeably thicker, making it harder to manipulate at room temperature. Nevertheless, this is a solid product that sells for less than $1/g, making it the price/performance leader.

Gelid Solutions GC-Extreme

GC-Extreme is the best thermal paste in our round-up, maintaining a slim lead over the runner-up as long as you're using a heat sink with high mounting pressure. If this compound was a little softer, it'd be even more ideal and wouldn't require warming before application. Heating it up a bit does pay off though, and we recommend it for overclockers and enthusiasts. Due to its high viscosity, it's perhaps less ideal for beginners.

Noctua NT-H1

This paste is almost a classic by now, and it still gets widely recommended. Rightfully so? Our testing reveals that its price/performance ratio is almost as good as Gelid Solution's GC-2, and its thermal parameters are even better. Noctua's solution ends up in the upper mid-range of our contenders, and a low price makes it hard to pass up unless you're a hardcore overclocker.

Phanteks TH-NDC (Paste Bundled With Phanteks Coolers)

The paste that Phanteks includes with its heat sinks contains nano particles of diamond, approaches the thermal performance of Gelid's GC-Extreme, and can be applied as easily, if not more so. It is somewhat similar to Cooler Master's Extreme Fusion X1, but can be applied even by novices. A big shout-out to Phanteks for bundling TH-NDC with its coolers.

Pastes: Prolimatech

Prolimatech PK-1

If we were judging based on price, we certainly wouldn't call this an entry-level thermal compound. But how does it perform? Nano aluminum sounds pretty compelling, but the benchmark results are what matter to us. The PK-1 paste performs well enough, but doesn't blow us out of chairs. Really, it's the price that kills it. There are better alternatives out there, even if Prolimatech's entry-level solution is generally quite user-friendly.

Prolimatech PK-2

Yes, Prolimatech offers more than one thermal paste. The PK-2 compound in the green box sports better performance than PK-1. While it doesn't appear among the front runners, this paste is still in the upper mid-range.

Prolimatech PK-3

Prolimatech’s highest-end paste is more expensive than its other two models. Perhaps that yellow packaging is intended to suggest gold? This is a good thermal compound, but it's not the best one out there. It's also thick like the GC-Extreme, a product that the PK-3 can approach, but not quite reach. Warm this paste up before using it.

Pastes: Revoltec, Scythe, SilverStone, And Thermalright

Revoltec Thermal Grease Nano

No, this isn’t nail polish for female hardware enthusiasts; it's a liquid paste that's applied with a brush attached to the lid. Unfortunately, Revoltec's Thermal Grease Nano doesn't test particularly well. While it's easy to apply and remove, we measured lackluster thermal properties. Enthusiasts will want to stay away. At least it is inexpensive.

Scythe (Paste Bundled with Scythe Coolers)

Our tests with bundled thermal compounds continue. While Scythe's OEM manufacturer is unknown, at least the plastic bag has Scythe's name on it. The benchmark results come back average. They're not particularly good or bad.

SilverStone (Paste Bundled with SilverStone Coolers)

This is what you'll find when you pop open a heat sink from SilverStone. Although the syringe resembles the bundled pastes from be quiet! and Corsair, we come away with slightly different thermal results. The benchmark numbers aren't amazing. Rather, they fall into a range we'd consider pretty average. I wouldn't feel compelling to spend extra on aftermarket thermal compound, though doing so would yield better performance.

Thermalright Chill Factor III

For some reason, I only received a two-gram tube of this paste; the standard tube includes four grams. We generated some fairly average results with Chill Factor III as well. Consider this compound suitable for average users and beginners.

Pastes: Xigmatek

Xigmatek PTI-G3606

Xigmatek’s entry-level paste is called PTI-G3606, and it sells at a mid-range price. Measured thermal performance is acceptable and its ease of use is even commendable. At the end of the day, this is a solid product at a fair price for mainstream hardware enthusiasts. It's simply not what we'd recommend for more hardcore overclockers.

Xigmatek PTI-G4512

Xigmatek's premium thermal compound doesn't even cost more than its entry-level offering. But the trade-off for better thermal performance is higher viscosity. Before using it, warm this paste up. Although it's not really for beginners, we do get a good price/performance ratio out of the PTI-G4512 from Xigmatek.

Xigmatek (Paste Bundled with Xigmatek Coolers)

This is another paste bundled with a cooler we picked up off the shelf. In our tests, the freebie fares slightly worse than Xigmatek's low-end aftermarket stuff, but not by much. It's an average compound that you shouldn't feel compelled to shy away from.

Pastes: Xilence And Zalman

Xilence X5

According to our team in Germany, it appears that Xilence went out of business. Not that it matters much to our U.S. audience; the company's ZUB-XPTP.X5 thermal grease wasn't readily available here anyway. At least we have benchmark data for the compound in our charts for anyone overseas with it. In short, Xilence's X5 is suitable for entry-level systems. Just don't use it on an overclocked processor or a PC in Dubai.

Zalman ZM-STG1

Unfortunately, this one turned out to be a dud in our testing. Zalman's ZM-STG1 is easy enough to apply with a brush, but its effectiveness is sub-par. We'd consider it a notch above Revoltec’s competing compound, but not much higher. Overall, our measured price/performance ratio is a disaster.

Zalman ZM-STG2

The ZM-STG2 paste is priced comparably, but much better than the company's ZM-STG1. That doesn't make this offering good, per se. Surprisingly, both pastes share similar ingredient lists. The ZM-STG2 simply isn't watered down with too much silicone, and it remains tougher, even after burn-in.

Pastes: Just For Fun

Toothpaste

I made the mistake of buying a premium toothpaste with blue stripes through it. A cheap white paste would have probably fared better. Yes, you can use this stuff as a thermal compound, though its long-term stability is questionable and we wouldn't recommend it for overclocking. If all of the shops around you are closed, though, and you want to play a little Battlefield 4 on a new machine, you could probably get by for a couple of days.

Denture Adhesive

If you don't brush your teeth but do live with your grandma, denture adhesive could stand in for toothpaste during those same couple of days. Again, this is not a long-term solution. But then again, neither were grandma’s teeth (or yours, if you don't grab some toothpaste). Be careful with this adhesive. After burn-in, the cooler may stick to the heat spreader and prove hard to remove.

Results: Closed-Loop Liquid Cooler; High Mounting Pressure

I already described our test setup in Thermal Paste Comparison, Part One: Applying Grease And More. What follows is a performance chart on the liquid-cooled system employing high mounting pressure.

Results: Air Cooler; High Mounting Pressure

Likewise, we covered this configuration in Thermal Paste Comparison, Part One: Applying Grease And More. The following chart represents thermal performance of an air-cooled system employing high mounting pressure.

Results: CPU Air Cooler; Low Mounting Pressure

One last time, we covered this configuration in Thermal Paste Comparison, Part One: Applying Grease And More. This chart reflects our air-cooled machine with lower mounting pressure.

Results: Air-Cooled GPU; Medium Mounting Pressure

Our last bit of testing comes from applying these thermal compounds to GPUs, and the results are significantly different from what we saw cooling our CPUs.

The failure of some pastes may be explained by rapid hardening, and a second test with two additional cycles didn't change the outcome. What do we learn from those failures? While value-added pastes may work well with the CPU coolers they were bundled with, they may not behave well under the higher temperatures generated by powerful GPUs, and shouldn't be used with them.

It's Not As Easy As Picking A Favorite...

In the end, it doesn't necessarily matter how much you paid for your paste, or what thermal conductivity its manufacturer claims on the package. More important is the how: your application method makes or breaks this process.

Some of the pastes we tested remain classics, and are even relatively inexpensive. It only follows, then, that we'd caution you against spending big on a brand new paste that'll only make a temperature difference of 1 to 2 Kelvin. If that sort of delta plays a significant role in your overclock, you're courting disaster. Sufficient airflow through the enclosure should ensure that you're never dependent on a particularly high-performance thermal compound.

More hardcore overclockers tuning their systems competitively, or quiet computing enthusiasts who spin their fans down as low as possible for better acoustics might want to give more thought to their paste of choice. Even a majority of power users, however, should focus on a paste’s ease of use, leaning toward the softer compounds. A flawed application typically impacts thermal performance much more than the difference between pricey and value-oriented pastes ever could.

I don’t want to lift any one thermal compound up onto a pedestal, and I'm no fan of award inflation. Sure, I could drop a couple of favorites, but the assessment would be highly subjective because some folks weigh ease-of-use and performance differently. Moreover, a lot of these pastes perform a lot alike. We can still draw several conclusions from our work, though.

• Novices should gravitate to softer pastes and use the "lentil ball" application method
• Experts can warm up thicker pastes, making them easier to apply
• Softer pastes should be used with coolers that attach via low mounting pressure
• Pastes bundled with most CPU heat sinks are good enough
• Different rules apply for GPUs; you need to pick the compound you use on your graphics card very carefully
• While the legends spoken of liquid metals have a basis in fact, they are exaggerated

That’s it from my side. But let me also point out that our Thermal Compound Charts will be maintained with results from any new products that surface. What will I do with all the partially-used syringes and paste packs? Honestly, I don’t know. There's enough of this stuff around to last a lifetime...

Scythe has announced a new CPU cooler, the Kotetsu. The Kotetsu is a tower-style CPU cooler aimed at mid-range applications. The CPU cooler features an aluminum fin stack from which four individual heat pipes emerge. The heat pipes are 8 mm thick and are  made of copper. The aluminum fin stack has fins with varying patterns, the idea of which is to increase turbulence within the stack in order to increase heat transfer.

The cooler features a 120 mm PWM controlled fan, which can rotate at speeds between 400 and 1400 RPM. It'll push up to 79 CFM, and keeps the noise level below a maximum of 28 dBA. The cooler fits on most modern CPU sockets, including AMD's FM2+ and AM3+, as well as Intel's LGA 1150 and LGA 2011 sockets.

Scythe has priced the cooler at about $35.

Fan controllers aren't the sexiest items, let's face it. But Scythe is doing its best to make things exciting with its latest offering, the Kaze Chrono. The Kaze Chrono is a multifunction fan controller that goes beyond controlling your fans, throwing in a couple of extra functions just for fun.

The device occupies an empty 5.25 inch drive bay, allowing you to control your fan speeds, as well as monitor the temperature of your machine. When it's not doing either of those, it displays the time.

The Kaze Chrono is capable of controlling up to four fans and employs both the 5 and 12 volt lanes to do so. There's also a '12 Volt Spin-up' that ensures all fans are spinning properly before spinning the fans at your manually set speed. "Power Speed Control" targets malfunctioning fans by looking for fans running at 0 RPM for more than 15 seconds and cutting power to that channel automatically.

Temperature is monitored via six temperature sensor cables that come with the Kaze Chrono. A warning alarm will sound if the cables measure a temperature of 75 degrees Celsius or 167 degrees Fahrenheit. The cables are capable of measuring up to 100 degrees Celsius or 212 degrees Fahrenheit. The clock feature is powered by a Lithium battery and uses a 105 x 30 millimeter LCD.

Pricing is set at €27.50 and the Kaze Chonro is already available, though Scythe hasn't mentioned anything about pricing for the United States.

Follow Jane McEntegart @JaneMcEntegart. Follow us @tomshardware, on Facebook and on Google+.

Scythe has launched its new Grand Flex 120 cooling fans, a series of 120 mm axial fans that aims to be a successor to the company's well-received S-FLEX series and take it “to the next level in terms of design and performance.”

The Grand Flex 120 series features Scythe’s new “Sealed Precision FDB” technology for better lubrication and silent operation that utilizes high-grade lubricant oil between the shaft and the bearing that can withstand temperatures of up to 250°C. It is rated for a 120,000 hour MTTF (Mean Time to Failure).

The series also includes a new nine-bladed fan design with an indentation close to the center hub for more focused and concentrated air flow, a set of vibration dampers, and a 500 mm sleeved cable for use in larger enclosures.

The cooling fan series will be available in five variations to meet different users' requirements, including four fixed speed fans ranging from 800 – 2000 RPM and a PWM variable speed model.

The Scythe Grand Flex 120 is currently available with a recommended retail price of €10 ($13.29) for fixed speed models and €12 ($15.94) for the SM1225GF12SH-P PWM fan.

Scythe has announced a new CPU cooler, the Grand Kama Cross 2. This cooler is the successor to the original Scythe Grand Kama Cross. The cooler features a unique 'X-Stucture' design, which supposedly has higher compatibility with various motherboards and PC cases.

The unit is cooled by a large 140 mm fan that is PWM controlled. Its speeds can range from 500 RPM to 1300 RPM. At these speeds it provides noise levels from 13 dBA to 30.7 dBA, and airflow levels from 37.4 CFM to 97.2 CFM, respectively. The fan is also mounted to the heat sink using rubber anti-vibration pads.

The Grand Kama Cross 2 is also compatible with all modern CPU sockets, including AMD's AM3+ and FM2, as well as Intel's new LGA1150 socket and the LGA2011 socket. In its entirety, the cooler weighs 760 grams and measures 175.2 x 140 x 140 mm.

Included with the cooler is the cooler itself, the fan, thermal interface material, a backplate, a multilingual manual, and finally, a mini wrench.

The cooler is already available through select retail channels and carries an MSRP of €30.50 (excluding taxes), which translates to roughly $40.

Picking The Right Cooler For Haswell

After hearing about 5 GHz overclocks from pre-production fourth-generation Core processors (that's Haswell, for fans of code names), enthusiasts were despondent to hear that retail parts would be far less friendly. Angelini even went so far as to poll folks with hundreds of retail processors for his launch coverage in The Core i7-4770K Review: Haswell Is Faster; Desktop Enthusiasts Yawn. The consensus was that stability at 4.5 and 4.6 GHz on air was extremely rare, that most enthusiasts should expect to top out at 4.3 GHz or less using 1.2 V, and that heat is the most likely culprit.

Before we get into the details, let's have a quick look at the nine air coolers we'll be testing in today's round-up.

DeepCool’s Assassin and Phantek’s TC14PE return from our LGA 2011 round-up, ready to prove themselves against the more thermally-constrained Haswell package. The Assassin carries the Gamer Storm logo.

Prolimatech sent a pair of fans and alternative clips with its $80 PRO-GNSS-BK, pushing the as-tested configuration to $125.

Thermalright adds a second fan to its Archon SB-E, which now supports smaller LGA and even AMD’s sockets. Zalman updates its previously-reviewed CNPS10X in this Optima-version.

The Equalizer: Our Core i7-4770K Review Sample

One small detail that went largely overlooked in that already-mentioned launch article was voltage. Our source, whose retail processors were topping out in the 4.3 to 4.4 GHz range was only using 1.2 V to maintain low heat levels. After all, he's selling Haswell-based systems that need to remain stable through multiple years of warranty coverage. Meanwhile, I was pushing my press sample harder with 1.3 V. Was he being overly cautious? Was I too aggressive? Could my cooling situation really be that much better? Or might differences in stress testing account for everything?

One of our contacts recommended LinX to test the Hasewell architecture's advanced AVX 2.0 pipeline, suggesting it'd yield temperatures significantly higher than Prime95. Although we didn't see the delta he did, LinX does get somewhat hotter. It's even more taxing than the Intel stress test I used in our first Z87 Express motherboard round-up.

Switching to LinX broke my previous overclocking thermal limit at 1.3 V, forcing a drop to 1.25 V. The reduced voltage in turn dropped my “ragged edge” maximum to 4.6 GHz. Rather than trying to perfect that 4.6 GHz and worry about what might happen to it in the future as the sample started degrading, I informed today's invitees that we would test at 1.25 V and 4.50 GHz.

I also informed invitees that any cooler that allowed our CPU to bump the processor’s 100° Celsius thermal limit would need to be disqualified from this article’s conclusion.

Like the source Chris Angelini queried for his launch article, I could have also used 1.2 V to play it safe and limit my own overclocks to 4.4 GHz. But why would I do that? If I use my old MUX-120 review sample as a starting point, shouldn’t all of today’s top coolers be better?

Gamer Storm Assassin

Depending on where you look, you’ll find the Assassin CPU cooler sold under the DeepCool or Logisys brands, and perhaps as part number MC8000. The one thing both companies share is the Gamer Storm logo on the product and its packaging.

DeepCool didn’t need to specify any changes to the Assassin’s installation kit, since the mid-sized LGA mounting pattern is the same all the way back through the 1156, 1155, and 1150 interfaces. It’s also compatible with older LGA 775 and LGA 1366 boards, as well as the more modern LGA 2011. Its mounting kit is even able to replace the four-bolt bracket on AMD’s Socket AM2 through AM3+.

A decorative plated finish prevents oxidation of the Assassin cooler’s polished copper base, which comprises eight heat pipes to connect its pair of radiators.

The Assassin uses Intel’s LGA support plate as a spacer, preventing contact between its metal parts and any motherboard components, such as what we experienced in our recent System Builder Marathon. Rubber locating clips keep mounting studs in position without any crushing risks.

Assassin Installation

After positioning mounting screws on the cooler support plate (as shown on the previous page), the screws are inserted through motherboard holes (front-left in photo below), topped with plastic spacers (rear-left), topped again with mounting brackets (right), and then secured with nuts (right-rear).

A cross brace secures the Assassin cooler’s base to mounting brackets, using factory-installed spring-loaded screws to assure proper contact pressure.

The Assassin includes enough clips to install three fans and, unlike many competing products, the middle fan can be clipped to both radiators. Doing this reduces flex between the radiators.

Noctua NH-U14S

Unlike its monster-sized D14, Noctua’s NH-U14S uses a single radiator to reduce space, cost, and weight on the motherboard. Those sound like laudable goals as long as performance remains satisfactory, and the company offers an even-smaller NH-U12S for builds in more compact spaces.

A superbly-machined, polished, and plated base are intended to give the NH-U14S the best possible contact with CPU heat spreaders.

Designed specifically for mainstream platforms, the NH-U14S installation kit includes only a single socket support plate that fits Intel’s LGA 1150, 1155, and 1156. A second set of AMD-specific brackets use the motherboard’s integrated support plate.

The LGA support plate fits around Intel’s socket plate and rests upon the board, using a thin insulating sheet to prevent shorts. Though we expect this solution to suffice on microATX and ATX motherboards, contact pressure on nearby components could be a problem for certain mini-ITX-based solutions, as seen in our recent System Builder Marathon.

NH-U14S Installation

Studs on the Intel LGA support plate push through mounting holes from behind the motherboard (front-left, photo below) and are then topped with plastic spacers (front-right). Mounting brackets are next (rear), followed by nuts (rear-right).

A cross brace is factory-installed to the top of the NH-U14S base, as are a pair of spring-loaded hold-down nuts. These engage studs on the mounting brackets, and the springs assure appropriate pressure between the cooler base and CPU heat spreader.

Noctua also installs the NH-U14S' fan at the factory, though we removed it to access the front mounting nut in the above photo. It’s now clipped back into place.

Phanteks PH-TC14PE

The PH-TC14PE returns in red trim for our LGA 1150 cooling comparison, giving us a chance to see how a huge cooler that nearly topped our LGA 2011 charts copes with a tiny-but-hot overclocked Haswell die.

Oxidation-resistant electroplating in the PH-TC14PE’s finely-machined base is nearly translucent to provide optimal contact with the CPU’s heat spreader.

Relying on the original support plate for AMD’s Socket AM2 to AM3+ installation, the cooler’s universal Intel-compatible support plate uses the board’s smaller integrated socket plate as a shim. Thick rubber spacers minimize support plate warping, while preventing short circuits or crush damage on boards that have components near mounting holes.

PH-TC14PE Installation

Screws installed into the PH-TC14PE support plate (previous page) poke through from behind the motherboard (front, photo below). Plastic spacers (left-rear) support mounting brackets (right), which are then secured with screws (right-rear).

Phanteks adds a center screw to its cross bracket so that it won’t fall off when you install and remove the heat sink. Nuts on each end of the bracket engage studs on the mounting brackets, and springs on those nuts assure proper contact pressure between the cooler base and CPU heat spreader.

Phanteks includes enough clips to mount up to three fans, and bundles two fans in the PH-TC14PE’s stock configuration. The cooler base is up high enough to clear DIMMs up to two inches tall, and fans can be moved up or down on the sink for full memory clearance or added voltage regulator ventilation.

Prolimatech Genesis Black

Maker of the famous Megahalems heat sink, Prolimatech decided to change things up for its Genesis design by combining the benefits of both down- and cross-draft cooling. We received the even more exclusive Black version of this design.

Rather than take the typical one-size-fits-most approach, Prolimatech sells its heat sinks without fans. The Genesis includes clips for both 120 and 140 mm third-party fans (standard 25 mm thickness), and Prolimatech even offers a few fan models under its own name.

Most unusual of its fan products is Prolimatech’s 15 mm-thick 140 mm model. The firm sent a pair of these ($20 each), along with the special clips needed to use this nonstandard thickness on the Genesis ($5), adding a total of $45 to the cost of this $80 sink.

Oxide-resistant electroplating assures excellent contact between the Genesis’ finely-machined copper base and your CPU’s integrated heat spreader.

O-rings secure nuts to Prolimatek’s Intel-compatible support plate. The plate uses Intel’s socket backing plate as a spacer, and the nuts have shoulders to prevent pull-through. Though setup requires a little dexterity, the result is a mount that doesn’t create any clearance issues with nearby components.

Genesis Black Installation

Double-ended studs (left-rear in photo below) secure the support plate’s nuts (photo forward) to the motherboard, while additional nuts secure mounting brackets (top-right) to the studs.

Secured with ordinary screws, a cross bracket presses the Genesis cooler’s base against the CPU’s integrated heat spreader.

Your choice of fans are then clipped onto the heat sink’s twin radiators. This design allows one of the fans to cool the CPU, DRAM, and motherboard components simultaneously.

Worried about DIMM clearance? We’re not. Tall modules work fine. Rather, the parallel radiator’s primary drawback appears to be that it blocks DIMM access, complicating memory upgrades and diagnostics.

Scythe Ashura SCASR-1000

Sporadic availability has lead to wild price fluctuations in Scythe’s latest products, with the Ashura selling for anywhere between $50 and $80 when we can find it. Hopefully the firm stabilizes formerly-productive partnerships with major U.S. distributors.

The Ashura is, after all, one of the least expensive high-end coolers in today’s round-up, owing that description to its oversized radiator, 140 mm fan, and finely-machined copper base.

Supporting AMD sockets back to AM2 and Intel LGAs back to 775, the Ashura’s Intel support plate rotates to various positions to align mounting holes. Less-than-perfect for boards with mounting-hole crowding, we at least find rubber pads to protect those components from being crushed.

Ashura Installation

As with most coolers that employ standoffs, the Ashura uses insulated washers to prevent motherboard scratches and shorts. Those washers aren’t attached to the standoffs, however, and must be positioned over the holes first (bottom-left of photo below).

The standoffs (bottom-right of photo above) screw into corresponding holes in the under-motherboard support plate and are topped with mounting brackets (top of photo). Screws (top-right) hold the mounting bracket in place.

A cross brace installs over the Ashura’s base, screwing to the mounting brackets to hold the base tightly against the CPU.

The fan can be clipped onto the heat sink at various heights above the motherboard, providing either added DIMM clearance or added airflow under the fins, which can reduce a motheboard’s voltage regulator temperature.

SilverStone Argon AR01

SilverStone targets the Argon AR01 at value seekers, who can find the entire package for $35 at various sites. Though the modest price is matched by moderate specifications, budget-sensitive enthusiasts might find another advantage in an installation kit the lets it fit multiple platforms.

A proponent of direct contact with its heat pipes, SilverStone selected the three-pipe AR01 for this round-up specifically because of the Haswell core’s small heat spreader. Using the company's larger AR03 as an example, the outer pipes on that design don't make contact with the CPU. SilverStone does, however, increase the diameter of its AR01 pipes to 8 mm, up from the AR03’s 6 mm.

SilverStone’s machinists do a great job of leveling the base to maximize contact.

The AR01’s support plate features three holes on the Intel side to line up with LGA 775, 1150/1155/1156, and 1366. It also flips over to replace AMD’s default four-screw support clip system. Both sides use a thin, hard insulation layer to prevent shorts, though we’ve seen places where those wide tabs won’t fit.

Argon AR01 Installation

Insulated washers (bottom-center of photo below) protect the motherboard from bracket standoffs (right side of photo), which are screwed into the motherboard support plate. Mounting brackets top these standoffs, and are secured with nuts (top of photo).

Also secured by thick nuts, a cross brace holds the AR01’s base tightly against the top of the CPU. Cross cuts provide for compatibility with both Phillips and flat-head screwdrivers, in addition to an included wrench.

Synthetic rubber straps then connect the fan to the heat sink, preventing the transmission of vibrations. Unlike the rubber rivets used by some competing brands, SilverStone’s straps snap in from the side for easy removal.

Thermalright Archon SB-E X2

We’ve seen Thermalright’s extra-wide heat sink in a previous review, but the new version includes an updated installation kit in addition to its dual-fan (X2) name change.

The Intel support plate is now separate from the AMD plate, and includes a couple of special features to eliminate any conflicts with nearby motherboard components.

The bolts slide, with only a small portion of the bolt pressing against the board. That eliminates most of the on-board component conflicts experience with many competing products.

The bolts are also topped with insulating plastic washers, which add even more space for components that could be close to the mounting holes.

We still get the quality of a smoothly-machined copper base, which transfers heat to all eight heat pipes regardless of our processor’s small contact area.

Archon SB-E X2 Installation

Intel’s square LGA cooler mounts allow any cooler to be rotated 90°, but AMD’s rectangular bolt pattern doesn’t. Thermalright’s cooler bracket is notched on only two edges for AMD mounting, so the firm adds extra mounting studs to enable the same mounting flexibility on all compatible platforms.

Standoffs with factory-applied insulating washers screw into the support plate under the motherboard, and are then topped with the mounting bracket. The mounting bracket is secured with nuts.

The X2’s revised cross brace includes factory-installed mounting nuts on each end and a pressure-adjusting screw in the center.

After attaching the cross-brace to the mounting bracket, the pressure-adjusting screw is tightened to the specifications outlined in Thermalright’s manual. The lack of any torque indication on the wrench requires builders to use their best judgment.

User-applied adhesive rubber tabs reduce the transmission of fan vibration to the heat-sink’s cooling fins. We had to move these a few times to find the best position.

Xigmatek Dark Knight-Series Night Hawk Frostbourne Edition

If you like Xigmatek’s latest cooler, we wish you the best of luck finding it. After all, the company isn't big on model names, and online vendors are labeling this cooler by various versions of its extra-long name. What we have here today isn’t a failure to communicate, but instead a limited-edition white version of its Dark Knight II.

Xigmatek favors direct contact between its heat pipes and the CPU's heat spreader. It uses three fat pipes to achieve good coverage across the Haswell-based CPU's fairly small spreader. Its sanded finish is far smoother than it appears, and fills nicely with the tiny particles of silver-based thermal compounds.

A universal plastic support plate rotates into various positions to line up with Intel’s three LGA bolt patterns (775, 1150/1155/1156, 1366), and flips over to replace AMD’s four-bolt rectangular retainer. The wide tabs of this design work with most motherboards, though we’ve seen exceptions.

Night Hawk Installation

A fiber washer (bottom of photo below) prevents standoffs (right of photo) from scratching your motherboard as they're screwed into the support plate beneath the board. Mounting brackets top the standoffs and are secured with nuts (top of photo).

Chrome-plated spacers prevent the final set of mounting nuts from gouging an aluminum cross brace. The nuts are cross cut to support both flat-head and Phillips screwdrivers, in addition to an included wrench, and squeeze the base of the cooler tightly against the top of the CPU.

Rubber rivets secure the Night Hawk’s fan to heat sink fins, while preventing the transmission of vibrations.

Zalman CNPS10X Optima

Like one of its competitors, Zalman adds a channel down the center of its CNPS10X Optima heat sink to direct air, rather than let too much of the fan’s pressure escape from the sides. The cooler also features a universal support plate similar to that competitor’s, except for a few minor improvements.

Rather then use plastic, Zalman’s support plate is steel. It still flips over to accommodate Intel and AMD hole patterns, but uses threaded inserts and soft plastic insert holders to minimize motherboard contact and prevent annoying conflicts. Intel’s socket plate acts as a spacer to complete this low-impact design.

Zalman also puts a slightly different spin on the direct touch design concept by using four thin heat pipes instead of three fatter ones. Its base assembly is sanded completely flat, leaving only tiny sanding scratches to fill with thermal compound.

CNPS10X Optima Installation

The top side of the Optima’s base is made in two parts, and sandwiches mounting brackets between them. Screws on the bottom pull down on the plate above.

Shoulders on the mounting screws eliminate the need for standoffs, allowing the CNPS10X Optima to be screwed directly to its support plate.

The Optima’s fan clips into place, with a little flexibility in height adjustment. Raising it allows additional DIMM clearance and lowering it allows more air to pass beneath the bottom fins towards the motherboard’s voltage regulator.

Test Settings And Benchmarks

Asus’ top-overclocking Z87-Pro lays the groundwork for thermal testing, but not without compromise: knowing that CPU throttling would prevent accurate thermal measurement, I decided to prevent that occurrence by reducing core voltage to 1.25V.

LinX 0.6.4 is the new application that generates the most taxing thermals using Intel's diminutive Haswell die. I also warned cooler manufacturers that we'd have to drop them from contention if the CPU reached 100° Celsius, since throttling would prevent accurate readings above that point. For our part, I kept the room temperature below 23° Celsius. I further prevented the case from affecting thermal readings by leaving the motherboard in open air, hanging the board vertically to replicate its position in a chassis.

Lacking any mechanical support for a hanging graphics card, I used integrated graphics during these tests.

Results: Cooling And Fan Speed

The most noticeable feature of our temperature charts is the narrow range of approximately 12° between highest and lowest CPU core temperatures. Dismantled Core i7-4770s suggest that this is due to the interface material Intel uses. At best, this shows that huge improvements in cooling technology are needed to create relatively small drops in temperature.

The results are also the average of all four highest temperatures, and some cores run hotter than others.

Scythe’s Ashura is the hottest cooler to stay under the processor’s 100° limit at a room temperature of 23°. Zalman’s CNPS10X Optima failed the test at just over 21° room temperature, and hours of extra A/C were required to get the room cold enough to finish Argon AR01 and Night Hawk Frostbourne measurements.

We might have blamed Xigmatek’s white paint for the cooler’s inability to cope with a Haswell-based CPU at a mere 1.25 V, if not for the audible cues to fan speed. The slower speed likely corresponds to less airflow, though fin design is also a potential factor.

Noise And Acoustic Efficiency

We saw a fairly wide range of fan speeds, and some coolers even had two fans. Yet, the difference in noise between the quietest and noisiest model is far less than the 10 dB(A) that would indicate doubled volume in the (logarithmic) decibel scale.

The Gamer Storm Assassin and Argon AR01 are roughly 50% noisier than Prolimatech’s as-delivered PRO-GNSS-BK. Since Prolimatech's heat sink requires additional fans though (fans aren't included with the heat sink), the noise we're reporting only represents this specific $125 combined configuration.

The relative scale for cooling-to-noise calculations refers to how each cooler relates to the average of all coolers in today’s test. Dividing the group average by each cooler’s result gives a higher percent score for lower temperatures. Dividing each cooler’s actual noise level by the group average produces a higher percent score for higher noise. Noise, however, is the divisor, and higher divisors produce lower dividends.

The results use a 100% baseline. Since nothing can be more than 100% efficient, we zero out the chart scale by subtracting 100%.

Besides being the quietest product, Prolimatech’s PRO-GNSS-BK configuration is also the third-coolest. That combination gives the firm a significant lead in our cooling-to-noise calculations. Hitting the middle of our cooling scale, a second-place finish in noise measurements gives the Noctua a second-place acoustic efficiency finish. Phanteks and Thermalright are the only two remaining companies to beat the class average.

Cooling Value

We warned companies that any cooler that allowed our CPU to top 100° Celsius at 1.25 V would be disqualified from further contention, and found ourselves lucky that we were even able to get the room cold enough in July to finish testing. Of the coolers that survived our tests, Scythe’s Ashura barely qualified at a 98° maximum in a 23° room.

For many overclockers, that means Scythe’s top-value Ashura presents a worst-case cooling scenario, and that anything less powerful isn’t going to satisfy you if you're overclocking a Haswell-based processor. Noctua’s NH-U14S takes a distant second in value, and this $75 part is the cheapest (and hottest) cooler worthy of a full recommendation.

With a 29 decibel noise reading in our lab, Noctua’s NH-U14S climbs a little higher up the value chart when acoustics are considered. The top position of Scythe’s Ashura would qualify it for a value award, if not for the caveat that users must keep the inside of their case below 25° in order to make proper use of a modest 1.25 V overclock.

Which Heat Sink Best Contends With Haswell's Heat Problems?

Here's the bombshell we figured out from today's testing: for overclocking, a quad-core Haswell-based processor at 22 nm requires more cooling than a six-core Sandy Bridge-E CPU at 32 nm, even though its lower power consumption produces less heat. The back-up for this is that two of the coolers from our Sandy Bridge-E cooling round-up re-appeared today with far worse apparent performance. Most overclockers blame Intel’s newer integrated heat spreader and transfer material for this discrepancy. These days, cheap paste replaces solder for connecting the CPU die to the spreader.

Cross-compatibility between LGA 1150, 1155, and 1156 sinks theoretically makes it possible for us to test dozens of heat sinks and fans. Unfortunately, most solutions are too small to cope with the heat issues an overclocked Haswell-based CPU suffers. Since Haswell has the smoothest thermal throttling implementation I’ve yet experienced, I set a simple rule that any cooler that hit its threshold temperature (100° Celsius) would be disqualified from final consideration. That guideline prevented the submission of many samples, and even knocked three of the coolers we tested out of contention. But it left a hole wide open for one cooler to slip through at a maximum core temperature of 75° over ambient. Nobody should be expected to keep the inside of their case cooler than 25°.

With a moderate price and moderate cooling capability, Scythe’s Ashura SCASR-1000 would have received our “Smart Buy” award if we didn’t need to warn you to keep your case below 25° internally. We'll save you the conversion. That's 77° Fahrenheit inside your case, just to run a Core i7-4770K at 1.25 V. And the company might still have won that award if we lowered our overclocking parameters. We don't think it'd be fair to hand out a prize, since we announced the settings we'd be using during the invite phase. However, if your overclocking expectations are lower than 4.5 GHz, we think you'll be pleased with the Ashura.

The top-performing configuration in our review, Prolimatech’s PRO-GNSS-BK with dual PRO-USV14 fans and PRO-USB-ARMG adapter clips would likewise be a contender for our highest-end “Elite” award, if not for its total build price. If I'm an enthusiast looking for the best of the best, which is what wins an Elite award from us, then I'm going to go with liquid cooling rather than spending a total of $125 on those parts, though we have to give Prolimatech credit for an elite collection of cooling components. 

Noctua's NH-U14S isn't the strongest performer qualifying for our stamp of our approval, but it is the least-expensive option able to do what we need it to. Second place on our value charts behind the Ashura, which barely qualifies, the NH-U14S is effective enough to allow a 31° case temperature before our Core i7-4770K at 4.5 GHz started throttling under unusually stressful test loads. In other words, it allows us to get most of our intended performance most of the time.

If that sounds like a half-hearted justification, consider the field and consider our tepid response to Core i7-4770K in the first place. We aren't particularly enthused about Intel's latest effort, but Noctua's NH-U14S makes the best of a difficult situation.

Some of Scythe's new fans, the Grand Flex series, have been spotted on a Chinese website. This series of fans is detailed to start off with five 120 mm fans, all of which have a new, interesting blade design. It appears that the idea of this blade design is to provide better airflow while producing less noise.

The fans will come in numerous versions. They are all 120 mm fans that are 25 mm thick. Four of the fans are normal voltage regulated fans with three-pin fan connectors, and one of them is a PWM version with a four-pin fan connector. The voltage-regulated models have speeds of 800 RPM, 1200 RPM, 1600 RPM, and 2000 RPM.

There was no word on what the fans would cost, but they are expected to ship starting July 3, 2013.

Scythe has launched a new budget keyboard and optimal mouse set that they’ve codenamed the SCY-2IN1-SILENT. The keyboard features 109 “quiet” membrane keys with a 19 mm pitch and 3.2 ± 0.5 mm keystroke length. The mouse has the standard three buttons (including a scroll wheel) with a BlueLED sensor and a 1000 dpi resolution.

The Scythe SCY-2IN1-SILENT will be on sale on July 10 in Japan for ¥ 1,980 (approximately $20).

Scythe has unveiled the Kave Chrono (KM-07-BK), a fan controller designed for 5.25-inch drive bays that measures 148.5 x 83 x 42 mm and features a large brick-matrix LCD panel that can display temperatures, fan speeds and detect a stopped or failing fan.

The controller draws power from a single 4-pin Berg connector and features four 3-pin fan headers that allow speed adjustment of up to four independent fan channels.

The Scythe Kaze Chrono is expected to be released in July in Japan with an expected price of ¥ 3,980 (US $40).

Scythe has released five new case fans, four standard case fans, and one with PWM support. All of the fans are part of the Slip Stream lineup, and all are 140 mm in size. The case fans feature a smaller hub than usual, an interesting frame design, and mounting holes so that they can even be used in 120 mm fan mounts, assuming there is space, of course.

The first four fans are almost identical. The only difference between them are the rotational speeds, which range from 500 RPM to 1700 RPM. The SM1425XT12SL spins at 500 RPM, pushes 27.2 CFM and makes just 9.6 dBA of noise. The second, the SM1425XT12L, pushes 43.5 CFM at 800 RPM and makes 14.3 dBA of noise. The third, the SM1425XT12M, makes 23.2 dBA of noise when pushing 65.2 CFM at 1200 RPM, and lastly, the SM1425XT12M can push up to 92.4 CFM at 1700 RPM but will make 36.4 dBA of noise.

The PWM model,  the SM1425XT12M-P, will push from 27.2 CFM to 69.9 CFM, can spin between 500 RPM and 1300 RPM, and makes between 9.6 dBA to 24.7 dBA of noise.

The non-PWM models will retail for an MSRP of €9, and the PWM model will carry an MSRP of €10.

Need to add more ports to the front of your desktop? Scythe has the solution for you in the form of the Kama Panel 3.1 which slips right into a single 5.25-inch drive bay. Building on prior models, this latest version even includes a slot for mounting a 2.5-inch HDD or SSD like a huge 9.5-mm (max) SD card right through the front.

In addition to the drive slot, Skythe's new I/O panel features two USB 3.0 ports, a 3.5-mm microphone jack, a 3.5-mm headphone jack, and a card reader spanning three separate slots for (1) Memory Stick Micro aka M2, (2) microSD / microSDHC and (3) SD / SDHC / MMC flash media cards. There's also an HDD activity LED, a power button and a reset button.

On the right side of all this is a dedicated space for controlling and monitoring fan speeds and temperatures. This area contains retractable knobs for Fan1 and Fan2, and a 1.22 x 0.49-inch LCD display showing the speed of each, and the temperature at each fan. There's a button that turns the screen's backlighting on and off, another button that changes the readout from Celsius to Fahrenheit, and a third "mode" button.

"Users are able to connect up to two case fans on the rear side and control them by turning the retractable knobs," the company said. "Supplied connector cables support both 3-pin and 4-pin fan connectors, where the fan speed is only adjusted using voltage regulation. Kama Panel 3.1 is adjusting the voltage in the range between 3.7 and 12 volts. In accordance with the measured temperatures, users are able to set individual alarm temperatures between 40 and 90°C in 1 degree steps."

Overall the I/O panel measures 5.85 x 1.67 x 4.88-inches and weighs 6.98 ounces. The DC input is 5V and 12V, and the DC output is 3.7V (±10%) to 12V (±10%). The fan measurement range is 0 to 9.990 RPM and the temperature range is 32° to 199.9° Fahrenheit (0° to 100° Celsius). Included in the package are two sensor cables, two fan cables, a power cable, audio cable, a USB 3.0 cable and more.

Expect to see the device show up on Amazon and other retailers soon for around $43 USD before tax.

Going Hands-On With Corsair's Massive Obsidian 900D

When I tested Corsair's Obsidian 800D, I used two high-end graphics cards to fry eggs, prepare a fondue, and cook hot dogs. This time around I'll be a bit more serious. Don't expect to be bored, though. I'm still testing the company's latest effort in two completely different use cases. The first challenges the 900D in its stock configuration with two of the warmest Opteron processors I could find and two hot-running FirePro W9000 graphics cards. It's amazing how much heat you can kick out using OpenCL-enabled benchmarks on high-end hardware like this.

But our efforts don't end there. After benchmarking the first configuration, I swapped out all of the case fans, installed a fan controller and water cooling system, and replaced the Opteron-powered workstation with a highly-overclocked gaming setup. The pièce de résistance is a high-end audio amplifier I also deployed. Why? You only live once. That's why.

I enjoyed another benefit, too. Because the Obsidian 900D is more massive than a modern race car's chassis, man-handling this enclosure as I installed and removed high-end hardware scored me some serious cardio. I'm pretty sure I gained half an inch around each of my biceps, too. Who needs a gym when Corsair's Obsidian 900D is beckoning?

Shipping Box and Unpacking

Truly, this case presents a physical challenge for everyone, including the delivery guy who I'm pretty sure hates me at this point. Fortunately, the cardboard box looks more massive than the enclosure inside really is. Understandably, Corsair is concerned that external stresses could lead to minor deformations of the oversize chassis.

In the event that rough shipping does affect the Obsidian's integrity, you might find it difficult to close the lower doors. I put the 900D through my familiar tilt test, though this time with the goal of straightening out the case, and I succeeded. The white specks you see in the pictures don't come from paint imperfections, but rather a powder that clings to the paint. 

I don't blame Corsair for the bumps our Obsidian took on the way to our German office. After all, more crossbeams would make the 900D even heavier. The company claims that retail versions of the Obsidian will benefit from a change in packaging that should prevent similar issues. And who knows? Maybe someone in German customs is to blame. All of the heft may have screamed "I'm loaded with illicit drugs" or "Open me if you enjoy illegal arms shipments."

Box Contents

Corsair bundles plenty of screws, cable ties, and various small parts, but does not include a piezo speaker. Even as UEFI-equipped boards become more common, a majority still sport a speaker header for error diagnosis. Also, don't search the accessory box for an ATX12V extension cable; it is already mounted at the rear of the motherboard plate.

The instruction leaflet that came with our sample was a folded sheet of paper. That's hardly what we expected to guide us through the features and assembly of a flagship enclosure. For instance, there weren't any instructions on how to remove the top cover. Again, though, Corsair promises us that retail boxes will include more comprehensive instructions.

Specifications And Features

The Front Panel

Front-panel I/O is hidden by a lid. Behind it, you find the power switch, a reset button, four USB 2.0 connectors, two USB 3.0 ports, and audio I/O for a headset.

Case Layout and Architecture

Let’s have a look at the case's architecture from the left and right sides, with the bottom compartment's lid both opened and closed.

Outside Corsair's Obsidian 900D

Although this a huge case, its industrial design could best be described as minimalist or monolithic. Let’s instead call it timeless elegance; there are no styling gimmicks, and nothing about the enclosure reeks of pacifying a focus group. The advantage of this design philosophy is that, even after several years, it doesn't appear dated. You'll never feel embarrassed about any of the 900D's style elements. In short, I very much like what Corsair did with its latest Obsidian. And even though it appears to have sharp edges and pointy corners, everything is actually round and smooth. Big ups to Corsair for its aesthetic.

The Obsidian 900D's Stock Cooling System

You'll find a removable cover on top of the case with mounting holes and a fan grill pattern to accommodate as many as four 120 mm fans. You can also install a radiator, so long as it doesn't exceed 480 mm (18.9”).

Remember when I mentioned the incomplete installation instructions? Well, here's where you need to be careful. The correct way to remove this cover is moving it from left to right, ignoring significant friction that might suggest you're doing it wrong, until the cover pops off. Don't try to lift the piece up without first sliding it over to the right; the plastic hooks will shear off otherwise.

Around Back: The Rear Fan

Corsair installs a Hong Chen fan at the back of the case, which looks similar to the company's AF140, but isn't quite as high-quality. Air flow is good. However, the blower is just too noisy for my tastes, so I put it on my replacement list. Again, the fan does exactly what it's supposed to, I'm just very particular about acoustics.

What Corsair does 100% correctly is decoupling its fan from the chassis, right at the factory, using rubber grommets. This is exactly what I do with my own custom builds, and Corsair seemingly read my mind.

Up Front: Triple the Fun...Err, Fan

The three front fans receive the same assessment as the blower around back. They offer good air flow, but they're a little too audible for me. Similar in appearance to Corsair's excellent AF120, I'm adding them to my replacement list as well. With that said, I've seen plenty of premium vendors bundle junk fans with expensive cases, and I wouldn't call the Obsidian 900D's fans junk. There's an easy way to test for this. If you try to reduce the speed of a poorly-built fan with a controller, its air flow falls to nothing. That isn't the case here.

The three fans sit behind a removable aluminum panel. Behind that, but in front of the coolers, you'll find a hinged air filter that snaps open and shut. The following animation illustrates the air filter box:

Side Lids with An Air Filter

The purpose of these lids is obvious: they facilitate quick access to installed hardware without needed to remove the massive side panels. The lids are hollow, which means that they can suck air from the bottom into the case, as long as the enclosure's interior pressure is lower than the outside pressure. You can also install radiators for liquid cooling in the lids, though the designated mounts for those are found up on top of the case.

The fabric has magnetic edges, and thus holds itself in place. I prefer not to mount additional fans or radiators there, as air flow through the bare fabric is rather negligible.

Replacing The Fans With Quieter Alternatives From Corsair

Corsair could have shopped in-house for its ideal case fans. Since the company didn't, I'm taking the liberty of doing it now, spending just a few dollars more. I have an AF140 around back and three AF120s up front. The latter are tasked with pushing air into the case, while the former exhausts it out. Notice the two SP120s in the stack; those will be used later with Corsair's H100 closed-loop liquid cooler.

The SP120s ship with blue rings around the radius. However, Corsair includes patriotic red, white, and blue liners you can swap in or out to taste. In the shot below, you can see I color-coded my fans, putting red rings on those exhausting hot air and blue rings on the intake coolers.

The trio of replacements up front, which spin at 1,100 RPM, yield the most significant noise reduction. Once we get a fan controller installed, the acoustics become truly Zen-like.

The uppermost and middle front-mounted fans are responsible for blowing air over our graphics cards, while the bottom cooler pushes outside air to the power supply and three internal 3.5" drive bays (along with the SATA hot-swap tray). Because their responsibilities are different, so too should the speed at which they spin. Incidentally, that's why I decided to add a six-channel controller, adjusting each fan independently. Is there a good reason to do this? There's only one way to find out. 

Six-Channel Fan Control: Scythe Kaze Master Pro

I wanted a fan controller that'd at least somewhat match the 900D's design. After mixed experiences with touch-enabled controllers, I decided to grab one with knobs: Scythe's KM04-BK. It isn't cheap, but who would put a discount fan controller into a high-end case, anyway?

Six channels are exactly what we needed to support four case fans and the two radiator coolers. Although you can mount normal 5.25" peripherals (optical drives, for example) in the Obsidian 900D without using screws, that's not the case for shorter accessories like Scythe's controller. Screws were necessary, but they aren't any sort of hassle, and they actually improve front-panel alignment.

A word of advice about the fan connectors: it's all too easy to pull the power and sensor cables off of their respective headers when they're routed inside this case or any other. Prevent that by tying the cables together and attaching the bundle to the fan controller enclosure, as shown below. Corsair includes cable ties, and this is a good use for one of them.

Installing The Power Supply

Upright, And A Choice Of Left Or Right

There are two viable mounting locations for the power supply, so you can take your pick (unless of course you'd like to install two power supplies, which is also possible). In both cases, the PSU sits upright. This isn't particularly ideal for passively-cooled power supplies, but it shouldn't be a problem for units with fans.

The shot below shows that there's plenty of room, even for extra-deep power supplies. If your power source of choice is less than about 7.5" deep, you can mount a drive cage in front of it. Don't feel pressured to, though; this case already offers tons of interior space for storage.

The power supply sits on the bottom of the case, without any sound-proofing material. I don't think a thin rubber pad for isolation is too much to ask for in this price category.

I hooked up my microphone and concluded that relatively quiet power supplies probably won't present any vibration problems. But if you plan to mount an older PSU with a large or unbalanced fan, the lack of acoustic decoupling could result in additional noise.

Putting this minor concern aside, I wanted to address a more pressing question: does the upright position result in higher power supply temperatures? I measured Corsair's AX1200i sitting up and loosely positioned on its back, recording zero different between the two orientations.

Installing Hard Disks And SSDs

The Obsidian 900D sports a total of nine 3.5” bays. Drives are inserted from left to right, and thus sit perpendicular to the case. The uppermost cage can be removed and mounted below the external 5.25” bays or installed at the bottom of the case, in front of the power supply.

The caddies are made of plastic, and they allow tool-less drive installation. Locking or unlocking a loaded caddy into a cage is achieved with a lever that seems to work reliably (though empty trays are somewhat flimsy).

Each caddy sports rubber grommets that decouple mechanical disks from the tray, while holding the drive in place with a metal pin. The grommets do their job; my microphone didn't pick up any major vibration or audible resonance from the identical 1 TB Samsung Spinpoint F3s I used for testing. 

In order to mount a hard disk in the tray, each of the caddy’s side rails needs to be bent slightly, allowing you to slide the locking pins into the drive's mounting holes.

Installing SSDs or 2.5” Hard Disks

SSDs and 2.5” hard disks are too small to work with the locking pins. Instead, they have to be mounted to the bottom of each tray using four M3 screws. In this way, SSDs and mechanical drives can be mixed and matched inside the Obsidian 900D. When I'm working with lighter aluminum cases, I typically mount heavy disks near the bottom for a lower center of gravity. But in the case of Corsair's big flagship, you can really put them wherever you want.

SATA Hot-Swap Bays

Hidden behind the lower lid are six fixed 3.5” drive bays. The three on the right are set up as hot-swappable SATA bays. They accommodate the aforementioned plastic trays, and upon insertion, engage with a factory-mounted SATA port. The power pins in the backplane all connect to a single SATA-style power plug.

Installing Optical Drives

Adding an optical drive to Corsair's Obsidian 900D is as easy as it gets. You don't need any tools or screws. Instead, the drive is held in place by a locking pin on a bracket. The only time you'll need screws is if you install an extremely short component like our Scythe fan controller.

You don't have to pull off the case's front bezel, since each bay’s cover can be removed individually. What looks like brushed aluminum is, however, merely plastic with a faux aluminum texture. So be careful not to scratch any of the covers you need to use. Likewise, exercise caution removing the bay covers because the pins holding them in place could break off. Instead of tugging from the outside, try disengaging the pins from within.

As this case is very wide, its bay covers are a lot bigger than any 5.25" device you'll ever install. The result is vertical gaps to the right and left of your drives. I also noticed that, at least in the case of my Samsung Blu-ray drive, the mounting position is slightly behind the front panel itself, aggravating those gaps.

This particular design idiosyncrasy voids the Obsidian 900D's entry into America's Next Top Model. In comparison, the Obsidian 800D's front bezel is both smooth and unbroken, which we find almost beautiful.

Motherboard Installation And Cable Management

As you know, motherboard form factors don't end with ATX. The pre-installed black standoffs are indicative of the largest boards this case supports: HPTX, which measures 13.6” x 15” and is represented by EVGA's Classified SR-2 .

Looking at the back of the motherboard mounting panel and all of those cut-outs, it's evident that you have plenty of room for routing the largest bundles of cables. Three clamps help bring some order to the cabling chaos.

Thanks to a cavernous interior, motherboard installation is cake. Just remember to mount your rear I/O shield first. Ours fit the cut-out perfectly, requiring just the right amount of force to snap in snugly and securely.

Most of the installation tray cut-outs are covered with rubber gaskets. They're flexible enough to easily let cables through, but stiff enough that they don't fall out of their frames as you're trying to run wiring.

It was easy for us to route all of the cables around the installation tray's back side. Needless to say, there was no danger of this wide enclosure's side panel bulging out from cables pressing against it inside.

Audio Power: Our 48 W Scythe Kama Bay Amp Pro

Eager to find more hardware I could install in such a large chassis, I stumbled across an audio amp that's easy to work with.

There are two versions of the Kama Bay Amp: a Pro model that takes up two 5.25” bays and sports a pair of analog VU meters, and a regular version that consumes a single bay, offers less wattage, and makes do with smaller meters. Both of them feature adjustable backlight colors.

In order to mount the amplifier, remove its feet and side panels. At least, that's the theory. In our case, something snagged when we tried to slide the unit into a vacant drive bay. The culprits turned out to be two tiny, nonstandard guide rails in the 900D’s front-panel cut-out.

A pair of pliers and some gentle force rid us of the plastic rails, letting the amplifier slide into place. You don't need any screws; the Obsidian 900D’s locking mechanism secures the amp.

The amp's sound quality isn't bad, given its $100 price point. And an output rating of 2 x 24 W RMS should be more than enough for bookshelf speakers. Hopefully, this unexpected addition serves as an example of what can be added to a large tower. Let your imagination run wild.

Live and Loud: The Amplifier

The sound quality of this video leaves something to be desired, but that's our microphone's fault. The performance of Scythe's amplifier justifies its cost.

An Illuminating Case Mod

A huge side window like the one on Corsair's Obsidian 900D almost begs for some sort of internal illumination, and ever since the day one of my Christmas trees won an award for being tacky, I cannot past up a lighting challenge.

I opted for a three-foot long LED strip, which I installed by starting at the top-right corner and running it counterclockwise to the lower-left corner. It has an adhesive on the back, and simply sticks to the metal. On the left side, point it towards the enclosure's interior to minimize glare. If you want to do something a little different, you can buy remote-controlled LED strips or multi-color kits with effects. Just make sure they operate at 12 V so you don't need an external power supply.

The video below shows my install with audio control, enabled by CCFLs (cold-cathode fluorescent lamps), available for around $5 and up. To avoid clutter, you can hide the control electronics in one of the unused 3.5” drive bays.

Results: Temperatures And Acoustics

Measurements: The Workstation Build

The workstation build consists of two Opteron 4284 CPUs (AMD's Valencia design running at 3 GHz plus Turbo Core), wielding 16 total cores on an Asus KCMA-D8 motherboard. Two Noctua NH-U12DO A3 coolers keep the high-end combination running stably. We populate the platform with 32 GB of Kingston DDR31033 ECC-capable memory. Aside from our processors, the two other major sources of heat are a pair of AMD FirePro W9000 graphics cards, each of which employs a Tahiti GPU. Under load, the professional workstation cards draw more than 400 W.

Adding 250 W for the CPUs and a dozen or so watts for the hard drives, we have a 700+ W system that generates massive heat. A large tower case should be able to handle that easily though, right?

We load up each CPU core using LinX, and exercise the graphics cards with a mathematical simulation. When it comes time to take sound level measurements, however, I remove the graphics cards because their fans are simply too loud. They drown out what we're truly trying to evaluate here: the case and its fans. With a constant room temperature of 72°F and a microphone 20" away from the upper-left corner of the case, diagonally at a 45-degree angle, we look to replicate a user sitting in front of a workstation.

The CPU temperatures in the table below are the average T_core results for each CPU separately.

We can draw three conclusions after taking these measurements. First, the stock fans are still audible at 7 V, but they barely contribute to the case's cooling. Second, the graphics cards benefit more than the CPUs from a stream of cool air. And third, it is admirable how quietly and effectively the two Noctua coolers, positioned back to back, get rid of each CPU's heat. I adjusted the speed of Noctua's fans in such a way that they don’t interfere with each other, but form a cooling cascade.

Measurements: The Gaming Rig

Naturally, I also wanted to test a gaming rig, forgoing air cooling in favor of a closed-loop liquid cooler on our CPU. We ended up using Corsair's H100, sporting a large 11" radiator that gets swallowed up when we install it at the top of this Obsidian 900D. Although the configuration we're using easily handles the processor's heat, HIS' HD 7970 X² card, factory-overclocked to 1.3 GHz, dissipates a whopping 300 W. 

Once again, we used LinX to load up the CPU and an OpenCL-accelerated app to tax the graphics card. This system generated as much thermal energy as it could.

So, how does the gaming rig fare? Remember, we swapped out all the fans for this configuration and added Scythe's controller. As with the workstation, we yanked the graphics card for measuring the case's sound level. And the results are impressive.

Compared to the workstation test with its stock fans turned off, our replacements are less noisy spinning at 25%. How is that even possible? By switching over to liquid cooling, the processor heat sinks and fans get factored out. With one Ivy Bridge-based processor in the box and no graphics card installed, the system's total power consumption is only around 110 W. The result? Drastic measures yield drastic results. At 110 W, the gaming build comes nowhere near overwhelming the gigantic Obsidian 900D. Compared to the older Obsidian D800, Corsair got it all right this time around.

Corsair's Obsidian 900D: Big, Bold, And Beautiful

It’s not easy to write a record-breaking summary for the review of a record-breaking case without succumbing to the questionable practice of piling superlatives onto each other. The fact is, our few concerns about this case were promptly addressed by Corsair. Ultimately, this is an extra-large chassis that falls into a class of its own and lacks notable competition. Who needs such a colossus? I don’t know. But in the end I managed to fill it quite easily.

Let’s recap the high points. First, I have to bring up Corsair's subdued styling yet again. It's an almost genius-level minimalist design. Some enthusiasts may dislike the large side window. However, turning the inside of an enclosure into a light show was never so much fun. The Obsidian 900D offers an ideal shelter for exotic and extreme technologies, leaving no wish unfulfilled. Its rigid frame and practical partitioning into multiple zones let you live your dreams and install anything you can think of.

The stock fans are merely OK. Swapping them out for higher-quality coolers (even better models in Corsair's own portfolio work well) gives you the freedom to adjust fan speed across a wider range without compromising thermal performance. If you're picking up on my enthusiasm, you certainly aren't misjudging my fascination with this case.

Is This The Case For You?

Corsair's Obsidian 800D found a fitting successor in its larger brother, the Obsidian 900D. We only found a few issues to quibble about, and much more to like. We're fans of the solid construction and find the simple design to be classic. In our eyes, modest elegance trumps modernistic design stunts. This is what our mature tastes have evolved into. Even after a few years, this case is going to look good, exhibiting its timelessness.

While the motto "less is more" aptly describes the chassis' exterior design, the interior may as well go by "more is more." Gratuitous space is smartly partitioned, actively aiding (inspiring, even) more complex hardware projects.

All of these redeeming qualities compel us to honor the Obsidian 900D with an award, which doesn't happen very often, particularly in the chassis segment. But we're certain that our recognition is completely justified and well-deserved.

While many people are switching over to the cloud for data storage and transfer, Scythe has decided to give those among us who still use memory cards and USB sticks some love. While we question the need for yet another 3.5" card reader, this is one that we can certainly welcome.

Scythe's Kama Reader 3, the SCKMRD3, is bringing some USB 3.0 goodness to built-in card readers. Previously, these card readers were limited to USB 2.0 speeds, but this reader would, of course, be a lot faster. While most cheap memory cards might have trouble saturating USB 2.0 bandwidth, there are a lot of photographers with much pricier, faster and bigger compact flash and SDXD cards that can go well over USB 2.0 speeds.

Scythe has even given us some benchmarks, showing more than double the read speeds on a 64 GB Transcend SDXC card.

So far there has been no word on US availability; however, the product has already hit shelves in Europe for a price of about €20, translating to roughly $27.

Based on the design structure of its predecessor, the Grand Kama Cross 2 has slightly improved placement of the fin stacks for better fan flow, and as a result, better thermal dissipation. Scythe claims that with the top-flow “X Structure” design, the heatsink is even capable of cooling areas of the motherboard surrounding the CPU. The Grand Kama Cross 2 features four 6mm heat pipes which intertwine each other and lead down to a nickel-plated copper base.

The new Grand Kama Cross 2 also features the new Hyper-Precision Mounting System (HPMS), which is a new and improved retention system aimed at making installation much easier. If you're worried if the new Intel Haswell chips will support this new technology, don't be, because they do!

The cooler is also equipped with a single, but powerful 140 mm Scythe Falcon fan which is capable of pushing 97.18 CFM.

The Grand Kama Cross 2 is expected to be available late April, and is priced at approximately $50.

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Scythe has launched the Mugen 4 CPU Cooler, which as one might expect, iterates on its predecessor and features the same "jagged aluminum fin" design with six 6 mm copper heatpipes conveying heat from a nickel-plated copper base.

The CPU cooler features the company's new Hyper-Precision Mounting System (HPMS) which requires fewer steps to install and has support for all modern CPU sockets, including the LGA1150 socket utilized by Intel's upcoming Haswell processors. Scythe has also modified the fin-stack arrangement to incorporate a "three-dimensional multiple airflow pass-through structure" (TMAPS) that aims to improve air-flow and heat dissipation.

The Mugen 4 measures 130 x 88 x 160 mm, weighs 625 g and features a Falcon 120 mm PWN fan that is capable of moving between 20.7 CFM (400 RPM) and 79 CFM (1,400 RPM) of air.

The Scythe Mugen 4 is expected to release in Japan on April 24, 2013 with a retail price of 4,980¥ ($50).

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Scythe has announced the Kama Bay Amp Pro, a generously equipped amplifier which users can mount in two 5.25" drive bays.

To begin with, the unit has a RMS power of 48 watts, 24 per channel, a total of four analogue input channels and an expected frequency range that goes from 20 Hz up to 20 kHz. The amplifier has 3 RCA female tulip inputs mounted on the back and so are accessible from inside the case and a single 3.5 mm input jack on the front. All of the Karma Bay's inputs and speaker terminals are gold plated and the latter terminal also has support for banana plugs.

The unit also features USB passthrough support, treble and bass adjustment and comes with a remote control which allows users to choose from the four input channels, mute, LED color, power, volume and treble and bass adjustment. It is worth nothing that the remote has no media keys and so users will not be able to directly control their media with it.

Since the amplifier does not draw power from the PSU, it comes with an external power brick and makes it entirely possible to use the amplifier as a standalone unit or mount it outside of the enclosure. Scythe also bundles in a variety of different cables and two expansion slot covers with gaps to assist in cable management.

Scythe's Kama Bay Amp Pro is available with an MSRP of €84 which translates to roughly $110.

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The Scythe Ashura comes with a fan that they call a 'Hayabusa' fan. This fan will operate from as low as 300 RPM up to 1300 RPM. It measures 140 by 140mm, and has noise levels ranging from 13.0 to 30.7 dBA. It also pushes from 37.37 to 97.18 CFM and the fan is PWM controlled.

The heatsink weighs in at 750 grams and is built using six 6mm copper heatpipes. The unit also has support for an additional 140mm fan using the shipped bracket.

Scythe's new Ashura CPU cooler will fit on all common CPU sockets including Intel's LGA 1155, LGA 1156, LGA 1366, LGA 2011, along with AMD's AM2, AM3, AM3+, FM1 and FM2 sockets.

The Ashura CPU cooler will go on sale starting February 6th and has an MSRP of $55.

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PSU Manufacturers, Designers, And Labels

Update: 1/23/13: Due to overwhelmingly positive feedback and a number of reader questions about the actual origin of certain power supply brands, we thoroughly revised our Who’s Who of PSUs, originally published in November of 2010 and last refreshed in May of 2011. Since the article is frequently quoted and linked to, we’re updating it rather than publishing the newest entries. As such, much of the content remains unchanged from the previous version.

Today’s revision adds many new manufacturers and brands, though. It also expands the number of models in several product families. Indeed, much has changed since our original article appeared more than two years ago, and we’re happy that readers in our forums and around the Web appear to be better informed and more discriminating when it comes to picking out a new power supply.

At the same time, manufacturers also appear to have re-evaluated some of their practices, and we’ve seen newer models use better components, resulting in higher quality overall.

We want to extend a special thanks to our community, as many of our readers and forum members have contributed much helpful information and valuable data to this analysis.

Several companies also joined in for the first time, volunteering information on their product lines. Sadly, for now it still appears that this is the exception rather than the rule. Many of our emails asking for information were met with silence. On that note, we acknowledge that we’re not infallible. Should you come across any omissions or errors, big or small, we invite you to send us your feedback so we can keep expanding and refining this list, ensuring it remains current and as inclusive as possible.

This article first appeared on November 12, 2010, and has since been added to and updated.

Who’s Who?

Let’s start by dividing the manufacturers into three large groups so we can better understand the database and how these companies are connected:

1. The OEMs (Original Equipment Manufacturers)

OEMs manage all of their production internally. They either exclusively design and manufacture their own PSUs (like Enermax) or design and manufacture their own brands, as well as manufacture PSUs designed by other companies (such as FSP, HEC, and SeaSonic). Some of them focus heavily on worldwide exports and provide a range of models, which are then sold under different labels. It's common to find otherwise-identical models marketed under many different names and labels. The industrial areas around Shenzhen, China, are the cradle of the lowest-priced PSUs sold all over the globe.

2. Designers: Without Their Own Production

The second group of companies also develops and designs their own products. However, they have to outsource either some or all of the manufacturing to other companies. One example of this is Be Quiet. Those familiar with the brand noted how Be Quiet P7 models were suddenly much better than the disappointing P6. The answer was simply a manufacturer change, from Topower to FSP. Other examples of designers include SilverStone, Corsair, PC Power & Cooling, and Tagan.

3. The Labels: With or Without Any Technical Involvement

Arguably, this group could be subdivided. Some importers of foreign PSUs that resell models under their own labels have a certain influence over the quality and choice of components, while others simply bring in some very cheap products, change the label, and resell them.

This third group is the most interesting one for price-oriented customers, though also the most uncertain for quality. You're as likely to score a bargain by getting a relabeled high-quality product at a lower price as you are to be disappointed by being too tight-fisted. Some good examples of products to watch are new models from Aerocool, which are essentially the Cougar units from Compucase/HEC with a discounted price and completely restyled exterior.

After many tests and inspections of budget models (by us, our readers, and friendly computer stores), we would advise you to steer your piggy banks clear of the labels Rasurbo, Inter-Tech (Sinan Power, Coba), Tech Solo, LC Power, RaptoxX, Tronje, Xilence, Ultron, World Link, Q-Tec, etc. We were able to identify some of these models without looking at the UL number simply by checking out the installed components. These were almost exclusively the simplest work of such manufacturers as Enhance, World Link, Andyson, Topower, Casing Macron, and Channel Well.

Lack of protection circuits, low efficiency, and bad build quality were major points of criticism. The lowest of the low was a European label called Hardwaremania24, targeted at OEM PCs. While still in standby mode, the PSU heated to about 176 degrees Fahrenheit, spent the next six hours billowing smoke, and finally made what might be described as a trumpeting sound before dying. The host computer was never even turned on. After analyzing the PSU, we found no protection at all save for a single slow fuse.

Firecracker Or Power Plant?

How do you identify a bad power supply before buying it?

• Extremely high wattage claims at comparatively low prices are suspicious. There are simply no decent 750 W power supplies for $50. For every product class based on performance and features, there must be a minimum price. When a product is significantly below that price, be cautious. You can get a "400 W PSU" for $20, and such fire hazards are installed in budget PCs every day by unscrupulous companies that know exactly the risk they're handing off to buyers.

• Check the specifications. For example, if a PSU claims high performance on the 3.3 and 5 V rails while the 12 V rail numbers are low, then you know something is wrong.

• The manufacturer does not specify any combined maximum performance, but instead only shows the maximum load for each rail separately. This is done without specifying how much real power would be available if all rails are used at the same time. Avoid PSUs without this information.

• Be careful with juicy marketing expressions and commercial lingo: Super, Extreme, Gaming, Combat, etc. Using superlatives to describe something quite normal should arouse suspicion and have you double-check specification details.

• Passive rather than active Power Factor Correction (PFC) leads to lower power efficiency.

• Very few or short power connectors and cables might be an issue. A 750 W PSU usually has four PCIe connectors for graphics cards (2 x 6-pin and 2 x 6+2-pin), so think twice if a model only offers two (or at least consider your upgrade options).

• With cheap PSUs, the quality of the cable insulation may be poor, or the cables may not be insulated at all. The power cable grommet may also be insufficiently padded.

• Be careful if there are few or no indications of protection circuitry. If the PSU specification only says OPP (overload protection) or perhaps SCP (short circuit protection), this points towards a normal fuse. If the specification also says OVP (overvoltage protection), this probably means that it is equipped with a simple metal oxide variable resistor. These security measures by themselves are absolutely insufficient and cannot replace any kind of digital safety chip. 

Unfortunately, you can't always tell at first glance whether you're dealing with a high-quality PSU or whether there's nothing but disappointment waiting behind the pleasant facade. Therefore, we decided to open up two budget PSUs representative of what you can find in many of today’s OEM PCs and illustrate the points and features you should be examining.

A First Look At the Inside: Primary Capacitor and PFC

First, look at the storage capacitors in the primary circuit. These act as buffers and help protect the PSU and computer from voltage fluctuations. The electrolyte used in them is key, because it evaporates or dries out through a combination of heat and time. As a general rule, capacitor lifetime is halved for each 10 degrees Centigrade increase in temperature over the specified normal load. Using higher-quality capacitors that can handle 105 degrees instead of 85 degrees (C) should almost double their lifetime, greatly contributing to the PSU's durability.

A PSU equipped with a big choke like in the photo above is a clear indicator of passive Power Factor Correction (PFC). Only more sophisticated active circuitry allows for factors close to the optimum value of 1, while passive components can reach 0.7 to 0.8 at best. The type of power factor correction indirectly suggests the expected efficiency of the power supply. Although PFC and efficiency are casually unrelated, devices with active PFC are also usually more complex and modern, meaning you're more likely to get better efficiency from them.

Protection Circuits

Even without opening the PSU, a data sheet can reveal some of the safety measures taken (or not) by manufacturers. A decent PSU should contain the following safety measures:

• OCP (Over Current Protection): protection against power spikes
• OVP (Over Voltage Protection)
• OPP (Over Power Protection): overload protection, sometimes called OLP 
• OTP (Over Temperature Protection): protection from overheating 
• UVP (Under Voltage Protection) 
• SCP (Short Circuit Protection) 
• NLO (No Load Operation): this isn’t exactly protection in the same sense as the other features, but it allows the PSU to power up and function normally, even with no load.

Without this information, you have to look inside the PSU to find out what you need to know.

We found no protection at all on this unit, except for a simple fuse. Sadly, this PSU is still available on the market under a couple of different labels.

Passive components do not guarantee sufficient protection. Without a digital security chip, the computer hardware is severely exposed to risks.

The security chip PS223 from Silicon Touch is popular, and you should avoid PSUs not using it or similar products, such as the PS332S.

Cables and Short Circuits

You can tell a lot about your PSU by looking at its internal wiring. A lack of heat shrink tubing, carelessly exposed solder joints, and components fastened with a glue gun are symptomatic of cheap and hazardous manufacturing. If unprotected cables are placed next to hot components, a PSU failure is nearly assured.

Boards

A final quality indicator is the circuit board material. Impregnated laminated paper (like the yellow boards in the pictures) is a sure sign of cost cutting. Fibre materials are much more durable and, perhaps more importantly, non-flammable.

How Do You Recognize The Manufacturer?

UL Numbers From Underwriters Laboratories

"Underwriters Laboratories, an independent firm working with product safety certification, has been active in the field of product testing and preparation of safety standards for more than a century. UL evaluates more than 19 000 types of products, components, materials and systems annually. Every year more than 20 billion UL marks are placed on products from 66 000 different manufacturers. The UL Group and its network of service providers include 68 testing and certification labs worldwide, serving customers in 102 countries."--From the About UL page at ul.com

Essentially, this means that all PSUs sold on the North American market must be marked with a UL number. This number should identify the actual manufacturer of a product. However, not every PSU has such a number. UL number omission on a North American product might indicate poor quality.

Step 1: Reading the UL Number

To find the UL number, there's no need to open your PSU or de-solder anything. Simply open your PC and look at the power supply's label. The UL number usually begins with an "E" followed by a string of numbers. See the three examples below.

If your PSU has such a number, you can move onto the next step, finding out what it means.

Online UL Number Query

Now let's find out more about your PSU. Go to the UL Online Certifications Directory and enter the UL number in the UL File Number field. If the number exists in the database, you should immediately see the result. If not, the number is invalid, fake, or the manufacturer no longer exists.

Link: Online Certifications Directory

PSU Makers: 0-9 And A-B

Companies: 2The Max Asia Pacific, 3Y Power Technology, Ablecom, ABS, AcBel, A.C.Ryan, Achme, A-Data, AeroCool, Ahanix, AHCOF, Aikou, Akasa, Amacrox, AMS, Aopen, Andyson, Antec, Aopen, Apevia/Aspire, Apex, Arctic Cooling, Artesyn/Astec, Astec Int. Ltd., Asus, Athenatech, ATNG, Atrix, Avance, Axle, AXP, Azza, Be Quiet!, Bestec, BFG, Bgears, Boser Technology Inc., Broadway.

PSU Makers: C-D

Companies: C-Young, Casecom, Casing Macron, Channel Well, Chenbro, Chieftec, Chill Innovation, Club 3D, CompUSA, Coba, Codegen, Comix, Conda, Cooler Master, Cooling Well, Coolmax, Cooltek, Corsair, Cresun, DAR, Dbetter, Deer, Dell, Delta, Dongguan Zhangmotou, Dynapower, Dynex.

PSU Makers: E-H

Companies: E-Star International, Eagle Tech, Elwin Technology Ltd., Elec, Emerson Network Power, Enermax, Enhance, Enlight, ePower, Etasis, Etopmay, Flextronics, Fob, Focus, Forepoint, Fortrex, Fortron, Foxconn, Foxlink, Fractal Design, Frisby, Fujitsu Siemens, Glacial Power, Gigabyte, Global Bright Intl., Globalwin, Gold Pal, GrowUp Japan, GPS, Great Wall, GTR, Guizhu, Hama, Hardwaremania24, HC, HEC, Highscreen, High Performance Group, High Performance PC, High Power, Himere, Hiper, Hipro, HP, Huntkey.

PSU Makers: I-M

Companies: ICP, Ikonik, Impervio, Inter-Tech, In Win, IOK, I-Star, Jada, Jeantech, Jet, Jehovah, Jersey, Jiumeng, Jiu-Peng, JOU JYE, JPAC, Just PC, Kaibo, Kaisen, Keega, Key Mouse, KinEagle, Kingwin, Koolance, L & C, LC-Power, Leadman, Leadway, Levicom, Li Shin, Lian-Li, Lite-On, Linkworld, Logisys, Mad Dog, Mapower, Masscool, MaxInPower, Maxtro, Mean Well, MGE/XG, Micor, Minlong, Mitac, MSI, Mushkin, Mutantmods.

PSU Makers: N-R

Companies: NesteQ, Newton, Nexus, Nipron, nMediaPC, North P, NorthQ, NOX Extreme, NZXT, OCZ, Okia, Pangu, PC Power & Cooling, Point of View, Powercase, PowerCooler, Powerex, Powerleap, Powerman, Powertek, Powmax, Procase, Q-Technologie, R-Senda/Rsenda, Raidmax, RaptoxX, Rasurbo, Recom, Revoltec, Rhombutech, Rocketfisch, Rosewill, RSD.