Sign in with
Sign up | Sign in
Antec Kühler Vs. Corsair Hydro: Sealed Liquid CPU Coolers Compared
By ,
1. Sealed Liquid Coolers Do Battle

The path to better PC component cooling has always involved bigger cooling surfaces, more airflow, or lower ambient temperatures. The problem with standard heat sink and fan designs is that the fans already hit the space limits of most systems, and making the cooler thicker can push its weight beyond the limits of the ATX form factor, causing bowing, bending, and sometimes even breaking. Noisy high-speed fans are required to maintain reasonable air velocity through the thicker sink, and pushing for the lowest ambient temperature often necessitates an acoustically-unfriendly chassis.

Liquid cooling conquers these challenges by relocating the heat sink to a more appropriate location, where it can be supported by the case and exposed to a cooler and/or higher-velocity airstream.

Moving the radiator away from the processor interface also benefits the builder, providing ample space to reach memory modules and on-board power connectors. And yet, maintenance issues often chase builders away from the custom cooling systems so often favored by our most enthusiastic readers. The alternative for low maintenance, sealed systems have become so reliable that they’re even being branded and sold by AMD (with its FX-series processors) and Intel (complementing the Sandy Bridge-E-based chips).

For as similar as the two coolers in the shot above seem, though, the included installation hardware is platform-specific. We decided that if we're going to spend big money on cooling, we want more universality than that. So, we chose to compare retail coolers able to support multiple platforms (two of which were produced by the same company as the platform-specific models).

Closed-Loop Cooler Features
 Antec Kühler
H₂O 620
Antec Kühler
H₂O 920
Corsair Hydro
H80
Corsair Hydro
H100
Length5.6"5.6"6.0"10.8"
Width4.7"4.7"4.7"4.8"
Rad. Thickness1.1"1.9"1.5"1.1"
Cooling Fans1 x 120 x 25 mm2 x 120 x 25 mm1 x 120  x25 mm2 x 120 x 25 mm
Total Thickness2.1"3.9"2.5"2.1"
Control TypeIntegrated/AutoProgrammableIntegrated/AutoIntegrated/Auto
Weight24 Ounces39 Ounces42 Ounces41 Ounces
AMD SocketsAll AM2 to AM3+All AM2 to AM3+All AM2 to AM3+All AM2 to AM3+
Intel Sockets775, 1156/1155, 1366775, 1156/1155, 1366775, 1156/1155, 1366, 2011775, 1156/1155, 1366, 2011
Web Price$58$95$75$95
2. Antec Kühler H₂O 620

In a partnership announced way back in January, Antec delivers the latest versions of Asetek’s LCLC cooling technologies in a retail package. The H₂O 620 represents its most-basic single-fan 1.1”-thick radiator version, intended for the rear panel of most performance-oriented ATX cases. Hoses are kept short to facilitate this installation cleanly.

AMD and Intel mounting kits are both included, though the version we received did not yet include the new LGA 2011 mounting screws previously seen in our PNY liquid-cooled GeForce GTX 580-based build.

Different holes in the socket support plate fit LGA 775, 1156/1155, and 1366 mounting holes. Plastic inserts in the top plate achieve the same purpose, while AMD gets its own support plates.

Factory-applied thermal compound covers the center of a finely machined copper cold plate beneath the H₂O 620’s pump. Tabs surrounding the pump body allow it to be installed in nearly any orientation.

A thin profile provides optimal installation space around the Kühler H₂O 620, even allowing access to our motherboard’s eight-pin EPS12V power connector. A lead on the pump facilitates automatic fan speed control, but this low-cost unit does not allow users to set a target temperature. Overclockers can achieve their best results by instead connecting the fan to a motherboard fan header.

3. Antec Kühler H₂O 920

With two times the fans and a radiator nearly twice as thick, the Kühler H₂O 920 is designed to be a big step up from its little brother. A push-pull orientation for the fans helps to overcome the reduced air velocity normally caused by a thicker radiator without a noticeable increase in fan speed.

The same CPU mounting hardware is used by both the 920 and 620 versions of Antec’s Kühler H₂O. Extra mounting thickness prevents us from reaching the motherboard’s EPS12V power connector, but we still had more than enough room to reach other motherboard connectors.

While dual fans and extra radiator thickness give the Kühler H₂O 920 its performance edge, the most interesting installation difference is the presence of a USB cable for controlling performance profiles. Users can select a wide range, from near-silence to stellar cooling from the Kühler H₂O 920’s software interface.

Antec Dashboard shows a coolant temperature that’s far below our processor’s internal thermal reading, along with the estimated noise level and speed of its fans and pump.

Graphing shows a brief history of liquid temperature and fan speed.

Default fan controls target a maximum coolant temperature of 50° Celsius. Evaluating the system’s maximum cooling potential requires setting the software's minimum selectable coolant temperatures of 20° to start and 25° max.

4. Corsair Hydro H80

January 2011 was a busy time for cooling companies. Corsair announced its switch to supplier CoolIT Systems at the same time as CoolIT released its improved cold plate design. Were that not enough to make our heads spin, Antec took Corsair’s place with Asetek. Phew!

The Hydro H80’s 1.5” radiator fits between its competitor’s single-thick and double-thick designs. And, it has a pair of fans similar to those of the competing double-thick solution. Selling for a Web price of $75, it also fits between the two competing models in price.

The H80’s Intel support plate uses slotted holes to fit a full range of LGA 775 to LGA 1366 coolers (with 1156 and 1155 in the middle). The first set of studs in the photo below holds the plate loosely in place behind the CPU socket.

A second set of studs holds the pump/water block atop LGA 2011-based CPUs, using the motherboard’s integrated support plate.

The H80 pump body ships with a matching set of Intel brackets installed. Included AMD brackets use wire hooks to engage AMD’s cooler clips. The pump body also includes a flow speed selector button and two four-pin PWM fan headers.

Thumb screws tighten the pump assembly’s cold plate against the CPU, pulling the socket support plate firmly against the back of the motherboard in this LGA 1155 installation. A small amount of space between the wider part of the stud and the motherboard prevents contact with any nearby circuit traces, which explains why the support plate was held so loosely in place.

5. Corsair Hydro H100

While the Hydro H80’s 1.5”-thick radiator was 50% wider than the 1” standard, the H100’s dual-fan radiator is nearly 100% longer. The top panels of many performance cases are designed specifically for this style of radiator, which is often called a two-by-120 mm design, abbreviated as 2 x 120 mm.

The H100 and H80 use the same pump style, though the H100 has four fan connectors as opposed to the H80’s two. Both have a finely-sanded copper cold plate with factory-applied thermal compound.

Both units also fit over the CPU in the same way, though the H100’s radiator is moved to the top panel.

The radiator’s top tank extends past the top of our rear fan, dictating its placement directly on the top panel.

6. Evga’s Air-Cooled Competitor

As seen in our previous Small Liquid versus Big Air comparisons, we wanted to include a high-performance air cooler to show what, if any, differences there are between the two technologies. Small liquid lost before, though this time we’re also considering noise, fit, and alternative radiator dimensions.

We picked Evga’s SuperClock CPU Cooler for its single 120 mm fan—which makes it a direct competitor to Antec’s Kühler H₂O 620—as well as its moderate price and good performance reputation.

Evga supports both AMD and Intel processor interfaces using the same installation plate. The firm has not added LGA 2011 mounting hardware yet.

Holes in the SuperClock CPU Cooler’s socket support plate fit most AMD and Intel processors. Thumb nuts make the included bolts stand up, while fiber washers insulate the motherboard from contact with the nuts. Evga even specifies adhesive film for the fiber washers to stick the plate in place, though we left the wax paper on this adhesive to ease removal.

The factory-installed mounting bracket supports everything from AMD’s old Socket 939 all the way up to Intel’s LGA 2011, though that'll require screws that Evga has not yet added.

The SuperClock CPU Cooler’s heat pipe-direct design reduces latent heat and weight. Several of our previous air-cooling comparisons have dispelled wild claims about this design’s performance advantages, though anything that can cut out weight without hurting performance is a benefit to us.

Spring-loaded nuts hold the SuperClock CPU Cooler tightly against the CPU.

7. Test Setup And Benchmarks
Test System Configuration
CPUIntel Core i7-2600K (Sandy Bridge), 3.40 GHz, Four Cores, O/C to 4.75 GHz at 47x multiplier, 1.38 V
MotherboardAsus Maximus IV Gene-Z: BIOS 0403 (06/27/2011), LGA 1155, Intel Z68 Express, O/C at 101.1 MHz BCLK
RAM8 GB G.Skill DDR3-2200: 4 x 4 GB, CAS 9-11-9-28, O/C at 1.65 V to DDR3-2158 CL 10-10-10-30
GraphicsNvidia GeForce GTX 580: 772 MHz GPU,  GDDR5-4008
Hard DriveCrucial m4 256 GB, SATA 6Gb/s SSD
SoundIntegrated HD Audio
NetworkIntegrated Gigabit Networking
PowerOCZ-Z1000M 1000 W Modular: ATX12V v2.2, EPS12V, 80 PLUS Gold
Software
OSMicrosoft Windows 7 Ultimate x64
GraphicsNvidia GeForce 280.26
ChipsetIntel INF 9.2.0.1019


We loved our recent Liquid-Cooled Gaming System so much that we decided to use it again in today’s cooler tests.

We removed its liquid-cooled graphics system to make room for these coolers, and its original power supply was also moved to other projects. A single reference GeForce GTX 580 stands in for graphics cooling, while OCZ’s high-efficiency Z1000M gives it big power with little cable clutter.

Benchmark Configuration
Prime95 v25.864-bit executable, Small FFTs, eight threads
RealTemp 3.60Average core reading at full CPU load (60 minutes)
Galaxy CM-140 SPL MeterTested at 1/2 m, corrected to 1 m (-6 db), dB(A) weighting
8. Benchmark Results: Temperature, Noise, And Acoustic Efficiency

Because liquid cooling systems are designed to be mounted in a case, we closed our side panels before taking thermal and noise readings.

Voltage regulator cooling is always a big concern whenever fans are moved away from the processor. Fortunately, Asus’ Maximus IV Gene is designed specifically for this type of build. As a result, we only see important differences in CPU temperature, where Asus' “Auto” fan control mode isn’t adequate for our overclock. Thermal throttling forced us to give up on automatic controls for the H₂O 620, so we tested it only at its maximum fan speed.

With a wide dual-fan radiator, the H100 easily tops our thermal charts. Meanwhile, Evga’s SuperClock tower-style heatsink and single fan prove the adequacy of cooling without pumps.


Automatic modes require a hot processor for evaluation, so isolating the cooler noise could only be achieved at maximum speed settings by connecting the fans directly to a silent 12 V power supply. Full system noise is far more pertinent however, and this is where hot temperatures give way to quiet measurements with the Kühler H₂O 920.

We calculated the average temperature and noise level for all coolers and developed a cooling-to-noise-ratio chart by simple division, which made the average 100%. Subtracting one from the result gives us a 0% average, where the charted results show gains or losses compared to the average of all coolers in this test.

Bold claims by Corsair and CoolIT about their new cold plate design are proven true in our Accoustic Efficiency calculations, which partly cancel out the benefits of super-fast performance- or super-slow silence-oriented fans. The Hydro H100 tops the chart, followed closely by its shorter/fatter H80 sibling.

9. Which Cooler Is Right For Enthusiasts?

With middle-of-the-road performance at a low price, it’s easy to see why so many builders continue to choose proven air coolers to maximize value. On the other hand, most enthusiasts want more cooling capacity, quieter operation, or some balance of those two characteristics.

Thus, a value chart like the one above doesn't really matter to the high-end buyers willing to spend big bucks on hardware, since it’s so heavily skewed by price. A look at the previous page’s cooling and acoustic efficiency charts give us the most useful information. And clearly, power users who simply want the best low-maintenance solution will take the closed-loop liquid route.

That’s also where Corsair’s H100 shines, though its lengthy design requires a specifically-designed case. While many of those cases exist, most builders don’t pick an enclosure based on its ability to accommodate a really big radiator.

Corsair’s H80 was the runner-up in both performance and noise, followed by Antec’s low-cost Kühler H₂O 620. A less than $20 difference between them seems like a pittance by high-end hardware standards. But the percentage is significant.

We’d have no problem running the Kühler H₂O 620 in most of our systems, even though its automatic fan control methods are completely inadequate for our build. That’s because we know that its three-pin fan can also be controlled by the CPU fan headers present on a few of our motherboards. Yet, the cost of switching up to a four-pin fan to make this part more universal nudges us even closer to the price of Corsair’s better-performing Hydro H80.

It appears that Corsair really does have the proverbial “better mousetrap” in its Hydro H80 and H100. The H80 fits more cases and costs less, so it gets our general recommendation for builders who want the performance of extra-big air, without the extra-heavy motherboard-busting heat sink. Now, let's see if enthusiasts pave a broad, hard-beaten road to Corsair's house.