Each year, we get asked by a number of enthusiasts if it's possible to build a passively-cooled PC and, if so, how much performance can be expected from it. And every year, we try to take a look at what is currently possible with a passive build.
Some of those configurations involve coolers that look like giant hamster wheels, while others employ large enclosures with more holes than Swiss cheese to let in plenty of air (and dust). This year, we want to build something plain and unobtrusive, not a bad piece of modern art. We're looking for an office machine that can handle some gaming in a small tower.

Given the hardware available today (and its relative efficiency), this is actually doable. Even still, we recommend a bit of insurance in the form of a barely-audible fan that can kick in if your more demanding workloads tax the hardware beyond what a heat sink on its own can dissipate.
But we’re getting ahead of ourselves. We're starting off with a basic build able to run some newer games at reasonable settings without a discrete graphics card. It's a little eerie: you have to wait until a picture shows up on your monitor to know the system is working, because you can't hear it at all. From there, we add a discrete graphics card to bolster frame rates in games, along with those aforementioned quiet fans.
Some Hard Choices
Like we said, an SUV-sized case with a gigantic cooler isn’t what we're going for this year. Been there, done that, and we still have such a machine sitting around gathering a lot of dust. Small and unobtrusive are the adjectives that matter most today.
After checking out the usual assortment of modern mini-towers and cube-shaped enclosures, our choice was clear: SilverStone's Temjin TJ08-E. It’s a classic tower-shaped chassis with several advantages that make it ideal for a passively-cooled build. For instance, its power supply isn’t just installed into the top of the case, like old-school towers. Rather, its orientation is also reversed so that the fan opening points upward. This effectively provides separate air circulation for the PSU and the rest of the system, and the exhaust port comes with its own dust filter. Talk about ideal conditions for a passive power supply.
You'll also notice that the motherboard orientation inside SilverStone's Temjin TJ08-E is turned. This means that the CPU and its cooler are at the bottom, with a lot of air above them. After taking out the hard disk cage and front fan, we’re left with a surprisingly large amount of internal volume for our passive build.
Packaging
The case is light and its packaging is simple and sturdy. It’s pretty easy to transport, and won’t break your mail carrier’s back.
Inside, we find the usual Styrofoam mess. You’ll want to have a vacuum cleaner handy after unloading the case, as bits of packaging are sure to fall like snow. There are cleaner ways to box up a case. Fortunately, some vendors seem to be listening, since we're seeing more foam-based protection, which doesn’t crumple into tiny bits.
In the Box
All that’s needed comes bundled with the case. You get screws, cable ties, a SilverStone sticker, a self-adhesive rubber pad, a USB 3.0-to-2.0 adapter for older motherboards, and a surprisingly well-written manual. We can’t even remember the last time we saw documentation that listed the maximum sizes for all possible components. It is this sort of information that makes deciding which case to buy much easier.
We were able to download the manual and check if the CPU cooler we wanted to use would fit before making any decisions. Big thanks to SilverStone for making the enthusiast's life a little easier.
Technical Specifications
Before we take a closer look at the case through a ton of pictures, here’s an overview of the SilverStone Temjin TJ08-E’s technical specifications:
| SilverStone Temjin TJ08-E Technical Specifications | ||
|---|---|---|
| Model | SST-TJ08-E | |
| Material | Front | Aluminum |
| Body and Sides | 0.6 mm Steel | |
| Form Factor | MicroATX, Mini-ITX, DTX | |
| Drive Bays | External | 5.25" x 2 3.5" x 1 |
| Internal | 3.5" x 4 2.5" x 1 | |
| Fans | Front | 1 x 180 mm (AP181) 700/1200 RPM with Switch 18/34 dB(A) (Downward Compatible, Holes for 140 mm Fans) |
| Rear | 1 x 120 mm (Optional) | |
| Expansion Slots | 4 | |
| Front I/O Ports | USB 3.0 x 2 (USB 2.0 with included adapter) Audio x 1 Mic x 1 | |
| Power Supply Unit (PSU) | Standard ATX up to 160 mm Length (180 mm Maximum) | |
| Maximum Graphics Card Length | 335 mm (with Drive Cage Taken Out) | |
| Maximum Fan Height | 165 mm | |
| Weight (without packaging) | 11.7 lbs | |
| Dimensions | Width | 210 mm |
| Height | 374 mm | |
| Depth | 385 mm | |
| Volume | 30.2 L | |
Front Panel
The case's front panel hosts the usual power and reset buttons, along with peripheral and audio I/O. SilverStone also exposes a switch for the 180 mm front fan's speed that's hidden somewhat on the right side. The fan moves a lot of air. However, it's anything but quiet, making it unusable for this build.
Dust Filter
SilverStone's Temjin TJ08-E has two dust filters: one in the front and one up top. The uppermost dust filter is held in place by magnets. This works well. It stays in place even if the case is turned upside down, but it’s easy enough to take off and put back on for cleaning.
Nestled inside the face panel, the front dust filter is not as easy to access (unless you have really long fingernails, that is). If you don’t, you’ll need some kind of thin tool to get it out far enough to grab on with your hands. Some kind of small handle would have been good here.
Fanless Power: SilverStone Nightjar 400W Zero dBA
SilverStone's Nightjar 400W Zero dBA is fairly heavy as a result of its completely passive design. Thermally, this power supply should work really well in the Temjin TJ08-E because of how it's built. The Nightjar’s current street price of $160 is high, but within reason. We won’t need the PSU's 400 W output by a long shot. Of course, we know that wasting power by buying too large of a power supply (and consequently not optimizing for efficiency) is a problem). But we're getting as close as possible with SilverStone's Nightjar 400W Zero dBA. It’s getting hard to find a PSU under 400 W these days, after all.
| SilverStone NightJar ST40NF Technical Specifications | |||||||
|---|---|---|---|---|---|---|---|
| Maximum Power | 400 W (Passive) | ||||||
| Voltage Rails | +3.3 V | +5 V | +12 V | +5 VSB | -12 V | -5 V | |
| Maximum (A) | 20 A | 14 A | 17 A | 2.5 A | 0.5 A | n/a | |
| Peak (A) | n/a | n/a | 31.5 A | 3.5 A | n/a | n/a | |
| Minimum (A) | 0 A | 0 A | 0.2 A | 0 A | 0 A | n/a | |
| Combined +3.3 V, +5 V | 130 W maximum | ||||||
| Combine +12 V | 324 W (27 A) maximum | ||||||
| Line Voltage | 99 V ~ 264 V | ||||||
| Line Frequency | 47 Hz ~ 63 Hz | ||||||
| PFC | Active PFC (PF>0.99 at Full Load) | ||||||
| Efficiency | 82% ~ 86% at 20% ~ 100% Load (80 PLUS Bronze) | ||||||
| Protection | OCP - Overcurrent Protection OPP - Overpower (Overload) Protection OVP - Overvoltage Protection UVP - Undervoltage Protection SCP - Short Circuit Protection | ||||||
| Connectors | 1 x 24 / 20-Pin Motherboard Connector (550 mm) 1 x 8 / 4-Pin EPS / ATX 12V Connector (550 mm) 1 x 6-Pin PCIe Connector (500 mm) 1 x 8/6-Pin PCIe Connector (500 mm / 150 mm) 2 x SATA x3 Connector (500 mm / 150 mm / 150 mm) 1 x PATA x3 Connector (500 mm / 250 mm / 150 mm) 1 x PATA Connector + 4-Pin Floppy Connector (500 mm / 250 mm / 150 mm / 150 mm) | ||||||
| Color | Silver | ||||||
| Cooling | Passive, No Fans, 0 dBA | ||||||
| Dimensions | Width: 150 mm Height: 86 mm Depth: 160 mm | ||||||
| Weight | 6.6 lbs | ||||||
Careful Installation
Installing the power supply takes some effort, and involves taking off the case’s top panel (the hard part) and then placing it inside the chassis from above (the easy part). The PSU's sharp edges can scratch the enclosure's finish very easily, so handle the hardware carefully during installation.
After the PSU is in place, it’s fastened from the back with four included thumb screws, making it easy to finish the installation. Too bad the screws and power supply aren't available in black, though.
The 400 W version of this PSU doesn’t have a status LED (the 500 Watt version does). Instead, the on/off switch lights up when the PSU is turned on. Using a motherboard that supports ErP/EuP, we measured an off-mode power consumption of only 0.4 W.
5.25” Optical Drive Installation
If you were worried that you’d have to go through a complicated process to remove the front of the case, we have some good news: once the drive bay’s metal cover is off, you can install your drive without removing the front panel. It’s nice to see SilverStone using metal there; it looks so much better than plastic.
Installing an optical drive in the Nightjar 400W Zero dBA does require tools, since small screws are included to secure the drive. Fortunately, this isn’t much of a hassle. As an aside, the two screws holding the bay’s cover in place are black, while the ones included with the accessories are silver.
Our Blu-ray drive fits perfectly, indicative of how well the case is designed and constructed.
Unfortunately, SilverStone's Nightjar 400W Zero dBA doesn’t feature a modular cable design, so cable management should be planned ahead with that in mind. It’s a good idea to use the first SATA connector on the cable for the optical drive. That way, the remaining cable can be hidden on the side of the case, behind the motherboard tray.
A Silent System Drive: Corsair Neutron GTX 480 GB
Large SSDs aren’t exactly cheap, but nobody said building a completely silent PC was easy. If only to satisfy our curiosity, we decided to use the 480 GB Corsair Neutron GTX. Our team in Germany hadn't used an SSD based on Link_A_Media Devices' LM87800AA controller yet.
As we know, Corsair buys the controller logic and flash memory used in its SSDs. This isn’t necessarily a bad thing, as long as the components work well together so that the finished product is solid. The GTX version employs MLC NAND with a Toggle-mode interface, which is the highest-end enthusiast-oriented flash we've tested.
Installation: Finger Exercise
The picture below does a good job of showing that the SSD needs to be screwed in very close to the bottom of the case. It’s located underneath the external 3.5” drive bay and still leaves enough room to install a 3.5” mechanical hard drive. Capacity-wise, 480 GB is enough for what we're doing, but it's still nice to have the option to add another drive. You could even use that space to install a second SSD using a 3.5”-to-2.5” adapter. Coincidentally, Corsair's Neutron GTX 480 GB comes bundled with one.
The screws on the very bottom of the case present more of a challenge when it comes to installing the SSD. We found that it’s easiest to turn the case upside down and hold the plate. You might even want to wedge a dry sponge in the 3.5” bay to pin the SSD in place.
We're still just a little put off by the combination of black and silver screws. Moving on, though, the installed SSD's connectors point toward the back of the case. So long as they're angled upward, SATA power connectors should fit. Fortunately, we found that the Nightjar's cables work well, so you won't need an adapter.
Choosing a Motherboard and CPU
We narrowed our choices down to two AMD Trinity-based APUs and a Socket FM2 motherboard. The APUs proved to give us the best balance between an all-around build intended to handle a variety of tasks, including light gaming. We did try an Ivy Bridge-based Pentium on one of Zotac's motherboards, expecting efficiency to seal the deal. However, graphics performance simply wasn't ample for what we wanted to do.
Thus, APUs were our only remaining option, so we picked the A6-5400K and A10-5700. According to AMD's specifications, both chips have 66 W thermal ceilings. In reality, though, the A6-5400K never reaches 66 W. The A10-5700 does, making a noticeable difference in trying to keep our system cooled passively. In the end, we're able to get both APUs cooled without a fan, but the A10-5700 cuts it close.
You may decide the A10 isn't the best choice, particularly in a warmer climate. If you do want one, we recommend adding a fan that kicks in when it's needed (we'll talk more about that shortly). First, though, let’s see how our two picks slot into AMD’s current line-up of desktop APUs:
| APU | Cores | Base Clock Frequency | Max. Turbo Core Frequency | GPU | Shaders | GPU Clock Frequency | L2 Cache | TDP |
|---|---|---|---|---|---|---|---|---|
| A10-5800K | 4 | 3.8 GHz | 4.2 GHz | HD 7660D | 384 | 800 MHz | 4 MB | 100 W |
| A10-5700 | 4 | 3.4 GHz | 4.0 GHz | HD 7660D | 384 | 760 MHz | 4 MB | 65 W |
| A8-5600K | 4 | 3.6 GHz | 3.9 GHz | HD 7560D | 256 | 760 MHz | 4 MB | 100 W |
| A8-5500 | 4 | 3.2 GHz | 3.7 GHz | HD 7560D | 256 | 760 MHz | 4 MB | 65 W |
| A6-5400K | 2 | 3.6 GHz | 3.8 GHz | HD 7540D | 192 | 760 MHz | 1 MB | 65 W |
| A4-5300 | 2 | 3.4 GHz | 3.6 GHz | HD 7480D | 128 | 723 MHz | 1 MB | 65 W |
Motherboard: MSI FM2-A75IA-E53
We picked a mini-ITX motherboard instead of an mATX board on purpose. Mainly, a smaller form factor keeps the case's insides as open as possible.
The enormous CPU cooler we're using makes connecting all of the cables somewhat of a challenge, though. In a couple of pages, we'll give you a brief guide for installing the motherboard; doing this in the right order is important.
| MSI FM2-A75IA-E53 Technical Specifications | |
|---|---|
| Socket | FM2 |
| CPU (Maximum Supported) | AMD A10/A8/A6/A4 Series |
| Chipset | AMD A75 |
| DDR3 Memory | DDR3 1066/1333/1600/1866/2133 |
| Memory Channels | 2 |
| DIMM Slots | 2 |
| Memory (Maximum Supported) | 32 GB |
| PCIe x16 | 1 |
| PCIe Generation | Second-Gen (1x16) |
| SATA 6Gb/s | 4 |
| RAID | 0/1/10 |
| LAN | 10/100/1000 |
| Trusted Platform Module (TPM) | 1 |
| USB 3.0 Ports (Rear Panel) | 2 |
| USB 2.0 Ports (Read Panel) | 4 |
| Audio Ports (Rear Panel) | 3+Optical SPDIF |
| eSATA | 1 |
| VGA | 1 |
| HDMI | 1 |
| VGA Maximum Shared Memory (MB) | 2 GB |
| DirectX | 11 |
| Form Factor | Mini-ITX |
| Dual Graphics Support | Yes (HD 6570, 6670) |
A Giant Cooler
SilverStone's Heligon HE02 CPU Cooler is truly a giant. Of course, that also means it's heavy. As you might imagine, that combination actually bodes well for this build. The Heligon employs a smaller number of fins spaced further apart than what you might be familiar with from competing heat sinks.
The first thing that catches our eye is the Heligon HE02's shape, which isn't a big block, like many other large air coolers. Rather, it resembles dual crosses. According to SilverStone, this helps maximize surface area. The Heligon HE02 is also asymmetrical, giving you a choice between using tall memory modules or our mini-ITX motherboard’s single PCIe slot.
The cooler weighs in at a hefty 2.18 pounds. Fortunately, the included brace makes it bearable for the motherboard.
The Heligon HE02’s base plate and heat pipes are made of nickel-plated copper, while the fins are aluminum.
SilverStone's Heligon HE02 is supposed to cool 95 W processors passively. That's probably a little too optimistic for the Temjin TJ08-E case, though. After a few modifications, the chassis did have enough internal volume to handle our APUs.
CPU Cooler Assembly
If you're looking to recreate this build, we strongly recommend reading the section on AMD-specific parts in SilverStone's manual very carefully! The backplate has an Intel side and an AMD side. First, the four preinstalled plastic Intel spacers need to be taken off. This isn’t mentioned in the manual. Then, an AMD cap needs to be added in the middle. Finally, four pieces of tape for electrical isolation have to be attached to the side facing the motherboard. Seriously.
The four installation pins that get pushed through the backplate are flattened to keep them from spinning when they’re screwed in from the other side.
The whole contraption is screwed together with thumb screws. Be careful that the installation frame sits very securely; after all, this cooler weighs more than two pounds.
The Right Thermal Paste: Cooler Master X1
Cooler Master’s X1 thermal paste is a really good product, but there are a few things to note about its application. The X1's 9.5 W/mK is at the very top end of current thermal pastes’ conductivity, which is ideal for passive cooling. Apply it as a small blob, rather than using the bundled putty knife. This isn’t the thickest solution on the market, but it’s not as viscous as Arctic’s MX-2 either. After a processor-friendly two-hour burn-in period, performance is measurably better than with normal pastes.
In a passive build, every degree of effectiveness counts. The best choice is really your only choice. We didn’t mess with any liquid metal thermal pastes, though, because you only get one try for correct cooler positioning. SilverStone's Heligon HE02 is large and not that easy to handle, so it might take two or three attempts until the cooler sits just right.
The picture shows the orientation we chose for the cooler, with the longer side over our memory modules (naturally, that means you have to install RAM before the heat sink). This allows the air to pass through the cooler from the bottom to the top, leaving some space between the Heligon and the back wall of the case, which could be used for something like an ultra-silent fan.
Making Some Room and Getting Rid of Some Noise
A few issues need to be worked through before the motherboard can be installed. In the shot below, you can see how many components could get in the way, negatively affecting the final build.
The hard drive cage, with its internal 3.5” bays, is first on our list. Thanks to our SSD and optional second 3.5” drive bay at the bottom, we can remove the entire cage.
After unscrewing just two screws, the drive cage is a thing of the past. This frees up a lot of room. Removing the adjacent 180 mm fan goes much the same way.
You actually need to remove the front panel in order to get rid of that 180 mm fan. Expect to use a couple of small screwdrivers and a lot of patience. While taking out the fan leaves a large hole, the air filter covers it pretty well.
Motherboard Installation
It’s finally time to install the motherboard. Or is it? As always, the I/O shield comes first. In this case, it needed an extra push or two to make it fit.
Now comes the hard part. The following installation steps need to be followed in precisely the right order. Let’s take a look at the motherboard with the cooler already installed. It’s oriented the same way that it’s supposed to be installed.
First, the 12 V CPU connector cable needs to be plugged into the upper part of the motherboard. Next, the front panel leads have to be attached, since the motherboard's connectors are somewhat covered by the cooler. The cables themselves aren’t very long, which makes it necessary to put the board in the chassis and tilt it backwards to access them. We used a 45-degree wedge made of wood and covered with foam rubber to keep the platform tilted up. You'll want to use something similar, or have someone ready to lend a hand for a few minutes.
Now it’s time to carefully lower the motherboard onto the spacers. The large cooler has a tendency to rip off the cables unless you hold onto them, making sure they stay put as you lower the board. These images illustrate what we're taking about pretty well.
It’s also a good idea to connect the SATA cables while the motherboard is still tilted. There’s enough space to install the 24-pin motherboard power connector, USB 3.0 connector, and HD Audio connector after the motherboard is installed.
And that’s it for the installation. Whew, it's finally all done!
Without a drive cage in there, the SilverStone case looks downright roomy. This allows enough chassis volume to cool the APU passively, though you still need to keep an eye on ambient temperatures. Summer weather without sufficient air conditioning can prove fatal for any passive system, no matter how large. Maintain a comfortable room temperature though, and you should be fine.
To protect the motherboard from the weight of its CPU cooler, SilverStone provides a holder that’s attached to the bottom of the case and can be adjusted to support the cooler.
Operation and Benchmark
The system is completely quiet. Once you push its power button, the only thing telling you if the installation was successful is a picture on your monitor.
We benchmarked the machine's power consumption and temperatures after burning in the APU for two hours. Power was measured with a current clamp on the 12 V line. Interestingly, the temperatures for the CPU and GPU, especially under load, were so close after two hours that the remaining difference was probably just due to the benchmark procedure. Because of this, we rounded all the numbers to the next full number. The ambient temperature was 22 degrees Celsius.


The outcome of the benchmarks was somewhat surprising. AMD's A6-5400K managed to stay within its thermal limit, but the A10-5700 exceeded it by 4 W in games and 11 W under a full load. This is still within reason, but needs to be taken into account when deciding the final system specs.
Under full load, the AMD A10-5700’s temperature jumps to 69 degrees Celsius if the ambient temperature increases to 30 degrees, which we simulated with an improvised hotbox. Even though 69 degrees is still within the APU's recommended range, and we didn’t see it throttle after four hours of testing, we still wouldn’t recommend running it at such a high temperature for long periods of time.
Case Evaluation: SilverStone Temjin TJ08-E
The reverse-mounted motherboard and the unusual PSU placement work out perfectly. SilverStone took a risk when it strayed from conventional wisdom as it placed this case's internals, and the gamble paid off. The advantages for our passive build are plain to see.
The quality of the case construction and materials is high. This includes an aluminum front that puts all of those plastic-faced panels out there to shame. On the inside, the CPU cooler holder is a nice and very practical addition, and the ability to easily remove a lot of parts gives you enough flexibility to utilize the TJ08-E for completely different builds. Even the one thing that annoyed us about this case is fairly minor. The supplied silver screws just don’t look good in the otherwise completely black case. Nonetheless, the Temjin TJ08-E and its included accessories are certainly worth the $110 price of admission.
Motherboard Evaluation: MSI FM2-A75IA-E53
Mini-ITX motherboards can be hard to find. MSI's FM2-A75IA-E53 FM2 mini-ITX board offers onboard Wi-Fi, Bluetooth, and a very good firmware that hosts a nice variety of interesting settings and overclocking features. All of this sells for $90, which is about par for the course in the mini-ITX market.
APU Evaluation: AMD A6-5400K and AMD A10-5700
Our game performance numbers, along with integrated versus discrete benchmarks, are spread across the following pages. Suffice it to say, we already know that the x86 cores in AMD's APUs are adequate. Fortunately, the faster A10 doesn't seem to slow down mainstream GPUs like AMD's Radeon HD 7750. In fact, the A10-5700 is quick enough for a quick game break after work, and it’s certainly fast enough for the productivity work while you're on the clock.
We have a harder time recommending the A6-5400K. It’s a reasonable choice for HTPCs, but that’s about it. The APU’s graphics engine just isn’t good enough for gaming. Performance comparable to a Radeon HD 5450 doesn’t cut it anymore, even when you take low power consumption into account. If you're building without a discrete GPU in mind, AMD's A10-5700 is the clear winner between the two APUs.
Cooler Evaluation: SilverStone Heligon HE02
Weighing in at more than two pounds, the Heligon HE02 is no lightweight. Neither is its $65 price tag. However, the cooler's passive cooling performance and installation flexibility (due to its asymmetrical design) help us get over the one-two punch of weight and price. There are few, if any, equal or better alternatives in this price range.
Installation can be a bit of a challenge if the cooler sits on top of connectors, but this can be overcome with some thought and planning. Overall, the SilverStone Heligon HE02 is a choice we're glad we made.
Thermal Paste Evaluation: Cooler Master X1
In the end, even the Cooler Master X1 can’t overcome physics. But it offers excellent performance after the proper burn-in period. Its viscosity could be a bit more toward the liquid side of the spectrum, but the blob application method yields a good outcome without resorting to a putty knife. The brand-new Cooler Master X1 is a nice addition to the market.
PSU Evaluation: SilverStone Nightjar 400 Watt Zero dBA
The SilverStone Nightjar 400 Watt Zero dBA offers passive cooling, 80 PLUS Bronze certification, and an ErP off-mode power consumption that’s a little under the mandatory 0.5 W. Its $160 price is a bit on the high side, but the ST40NF, and its larger sibling, the ST50NF, are built by Seventeam. This technology is tried and true, and these new versions are a good replacement for Etasis’ ST30NF. It would have been nice if modular cable management had been included at this price, which would have made the SilverStone Nightjar 400 Watt Zero dBA a better value. Nevertheless, cable lengths and build quality are good.
Bottom Line
As long as you aren't expecting high-end performance, it's possible to build a decent passively-cooled system powerful enough for light gaming. And you don't need to mount everything in a massive chassis, either. The A10-5700’s graphics performance is about on par with that of a discrete AMD Radeon HD 6570, which isn’t bad for this kind of build. It can compete with the inexpensive Nvidia GeForce GT 520-, 630-, or 640-based systems offered by the big-box stores, and it does so without making a sound. I actually use this PC in my office. It’s on 24/7, and I even wrote this story on it.
But That’s Not All…
You thought that was it? Not so fast! Read on to find out what happens if a passively-cooled Radeon HD 6670 is added, yielding a Dual Graphics configuration in conjunction with AMD's APU. We're even able to compare that setup to a passively-cooled Radeon HD 7750. Of course, as thermal output increases, we want to have a backup plan for evacuating heat from the case. We round out the build with a switch that controls an extremely quiet Noiseblocker Multiframe fan running at a barely-audible 750 RPM.
It’s hard to run several passively-cooled components in a small case like SilverStone's Temjin TJ08-E. Nevertheless, in addition to the build you just read about, we're benchmarking three different graphics setups: a HIS Radeon HD 7750 iSilence 5, Sparkle's GeForce GTX 650 OC that we modified for passive cooling, and a dual-GPU setup with CrossFire consisting of AMD's A10-5700 APU and a passive HIS Radeon HD 6670 iSilence 5.
Let's be clear: a small, enclosed system like this does reach its limits pretty quickly when an APU and discrete graphics card are taxed at the same time, dissipating 100 W+ of heat (particularly in the warmer summer months). But we think we have a solution for maintaining the integrity of our silent system for the most part. With a bit of tinkering, we added a quiet fan that only kicks on when it's needed. A good motherboard can control the blower through its firmware. Or, alternatively, a thermal switch does the same job. We’ll show you how to install a switch like this later in the story. For now, though, let’s get back to the build.
Silent and Efficient GCN
We’ve talked about HIS' Radeon HD 7750 iSilence 5 before. It features one of the most powerful GPUs you can find that can still be cooled passively. While Sapphire and PowerColor offer similar cards, all of them should function comparably.
The graphics card sits above our CPU cooler, obstructing some of its airflow and reducing its cooling performance a bit. The hit isn't massive, but it's certainly obvious when the system is pushed to its limit. If you already know going into this project that you'll be using discrete graphics, then an Ivy Bridge-based platform is almost certainly the way to go. That'll bring your temperature down about five degrees Celsius compared to the APU-based config.
Graphics Benchmarks
The Radeon HD 7750 easily competes with the other graphics solutions we're testing, and it offers the highest efficiency by offering the best performance for the power it uses. Nvidia's GeForce GTX 650 is roughly as fast.
But before we get into the details of that little project, let's have a look at the cumulative benchmark numbers with a Core i7, a Pentium G2120, and AMD's A10-5700. The performance index and benchmarks come from our 2012 graphics charts, and we used that machine's image for the AMD A10-5700-based build.

Bottom Line So Far
For a passively-cooled system, this thing's gaming performance isn't bad. It gives us high-enough frame rates for 1920x1080 in many cases, so long as graphics details are turned way down. Temperatures are also acceptable, though anyone building this PC should check them out anyway, just to be on the safe side.
Nvidia's GeForce GTX 650, Cooled Passively
The GeForce GTX 650 offers similar performance and power consumption as AMD's Radeon HD 7750. In theory, that'd make it a candidate for passive cooling. We weren't able to find a GTX 650 without a fan, though. So, we used Arctic's Accelero Xtreme III in place of the stock cooler. Nobody’s going to buy an expensive part like this to cool a mainstream graphics card, but it serves as a placeholder for similar coolers.

Installation is straightforward enough. The cooler's weight isn’t a problem because the graphics card is plugged in horizontally, with the cooler on top. So, the I/O bracket and PCB support its heft.
The same things we said about AMD's Radeon HD 7750 apply here as well. A system with a discrete graphics card benefits from an Intel CPU, which is going to run cooler and tolerate higher maximum core temperatures. So long as you use mainstream GPUs, though, neither a Pentium nor an A10 should limit your graphics performance.
Graphics Benchmarks

Bottom Line So Far
A passively-cooled GeForce GTX 650 comes close to the performance of a Radeon HD 7750, also with no active cooling. Again, this is to say that gaming performance is acceptable so long as you dial down your settings. It's too bad that there don't seem to be any add-in board partners selling GTX 650s with passive cooling.
Dual GPU: Performance Boost or Nonsense?
Even without the complexities of micro-stuttering, missing CrossFire profiles, and driver issues, we really don’t think that CrossFire makes much sense in this kind of build. Nevertheless, we gave it a shot anyway, if only to be thorough.
AMD recommends pairing our A10 up with a Radeon HD 6670 or 6570, so our passively-cooled HIS Radeon HD 6670 iSilence 5 was an ideal candidate.
In order to use the APU and a discrete graphics card in CrossFire, you have to enable the feature in your motherboard's UEFI. After booting back into Windows, CrossFire is good to go.
Graphics Benchmarks
Naturally, we weren't able to include the Intel-based systems in our CrossFire benchmarks, so the A10-5700 APU is all that’s left.

Bottom Line So Far
AMD's A10-5700 APU and Radeon HD 6670 in CrossFire are slower than a Radeon HD 7750, while using more power. The only reason to even consider such a setup would be to more completely utilize old hardware you already own. So much for that little experiment.
Temperatures Under Full Load
The ambient temperature while we tested was 22 degrees Celcuis (72 degrees Farenheit). Using a general-purpose computing application helped us tax the platform completely. A gaming workload allowed us to shave 8 to 10 degrees Celsius from our worst-case readings.

Bottom Line So Far
Thermals shouldn't be a problem so long as your air conditioner is working in the middle of summer. But just in case, let's look at what it takes to install an almost-silent fan.
Is This Thing On? Noiseblocker's NB-Multiframe at 750 RPM
Let's say your passively-cooled PC does end up in a room where it gets a little warmer than you'd like every so often. Installing a fan is inexpensive insurance, and it'll give you peace of mind that your hardware isn't baking itself. Noiseblocker's NB-Multiframe M12-S1 is an excellent choice for such an application because it’s not even audible from 50 cm away in an absolutely quiet room.
This fan should be used with its included vibration isolation pad. And there’s just enough space between the CPU cooler and the back of the case to accommodate this exact model.
You can plug the NB-Multiframe M12-S1 into the system or CPU fan connector. It really doesn't matter which you choose, since the cooler doesn't support PWM, and our chosen motherboard doesn’t offer simple voltage-regulated RPM control. None of that matters though, since running full-speed at 750 RPM is perfectly fine.
BIOS Trick
If you're using a PWM-capable fan, some motherboards can turn them off when they aren't needed. The feature looks like this in the BIOS:
The platform keeps the fan from spinning until a CPU temperature of at least 55 degrees is detected. This way, you enjoy complete silence under typical loads. We don't recommend pushing a target any higher than 55, though, because AMD's APUs are more sensitive to heat than Intel's CPUs.
Now we can tinker a bit, and build our own sensor-controlled on and off switch. The switch kit needs at least 12 V DC. Getting that from one of the power supply's four-pin connectors is easy enough.
In the interest of clean connections, the manufacturer of our switch tins the end of its wires.
The included sensor (a thermistor) can be attached with a cable up to one meter in length. We used about 30 cm of common copper litz wire and held the strands together with electrical tape.
The thermistor’s soldered connections need to be isolated properly so that they don't touch anything metal. This can be done with shrink tubing or just some electrical tape, though you should keep tape away from the hotter parts of the heat sink. The thermistor is glued onto the cooler with some of the same adhesive used to attach RAM sinks. If all else fails, wrap the thermistor in aluminum foil and attach it to a heat pipe using a cable tie. Whichever way you go, you'll want to secure the thermistor before you install the SilverStone heat sink to avoid getting your hands scratched up.
Pick the right temperature for activating the switch by applying a load to the system and watching its thermal status using Core Temp or AIDA64. In our case, we picked 40 degrees Celsius, measured at the back of the Heligon HE02 using an infrared thermometer.
The biggest risk in buying a hobbyist-oriented kit like ours that probably wasn't QA'ed very well is the potential of a dead component. We had to exchange it twice until we found one that worked the way it was supposed to. The key is to set on and off temperatures far enough apart, with the off temperature much lower, so that the switch doesn’t keep triggering on and off quickly (you'll know when you hear the relay click over). We had a lot of fun tinkering with this.
Modern energy-efficient graphics cards make it possible to game on affordable, passively-cooled platforms (and they don't have to be massive, either). Even without the "just-in-case" fan we've been talking about, you shouldn't encounter any thermal issues.
As with any build, you'll want to balance host and graphics processing performance so that you don't create bottlenecks. If you're using integrated graphics, AMD’s A10-5700 is a good choice. If you have a passively-cooled add-in board, an inexpensive Ivy Bridge-based Pentium or Core i3 is the better option. They run cooler, and at $100 for a Pentium G2120, they aren’t really any more expensive.
The much-touted Dual Graphics feature that lets you match an APU up to a discrete card in CrossFire is pointless. Current-gen passively-cooled graphics cards offer better performance and efficiency, and they don't saddle you with the problems of multi-GPU setups.
It’s too bad that we weren't able to find any passively-cooled GeForce GTX 650s. Do-it-yourself is the only way to go if that's the direction you head. You'll want to decide for yourself if a third-party heat sink is worth the extra cost.







































































