Cooling at Stock Speed

Some users will never overclock their CPU, but they still want to run the coolest CPU temperatures possible to enhance stability and extend CPU life. It is conventional wisdom that water cools better, but is that really true? The Swiftech H2O-120 Compact and Corsair Nautilus 500 both use high-output and relatively quiet 120mm fans - the same fan configuration used in the best air coolers. Both water coolers are reported, with the Corsair results in red and the Swiftech in orange.

X6800 Stock (2933MHz) IDLE Temperature

The very good Intel stock air cooler keeps the X6800 at 41C at idle, compared to the Corsair Nautilus 500 and Swiftech H2O-120 Compact which both kept idle temperature to a very low 26C. The 26C results are the best ever seen in AnandTech idle cooler benchmarking and match the top-performing Thermalright Ultra-120 eXtreme. The Tuniq120, the Ultra-120, and the Ultima-90 with a 120mm fan are one degree higher at 27C. All these results are dramatic improvements over the Intel stock cooler performance at 41C, and they represent an excellent performance by the water cooling kits, which match the best air cooler tested at stock idle.

Intel P35 Idle Stock Speed - Temperature in Degrees Celsius
Swiftech H2O - TAT 28
Swiftech H2O - CoreTemp 24
Corsair Nautilus 500 - TAT 27
Corsair Nautilus 500 - CoreTemp 24

Test results under the same conditions on the Intel P35 platform show the same pattern, but Intel TAT results are generally 1-2C higher than the NVIDIA Monitor results with the same CPU. CoreTemp shows idle temps about 2C cooler than NVIDIA Monitor.

It is more difficult to effectively simulate a computer being stressed by all of the conditions it might be exposed to in different operating environments. For most home users CPU power is most taxed with contemporary gaming. Therefore our stress test simulates playing a demanding game. The Far Cry River demo is looped for 30 minutes and the CPU temperature is captured at 4 second intervals with the NVIDIA Monitor "logging" option. The highest temperature during the load test is then reported. Momentary spikes are ignored, as we report a sustained high-level temp that you can expect to find in this recording configuration. This test configuration roughly equates to an 80% CPU load test using Intel TAT.

Cooling efficiency of the Corsair and Swiftech water cooling systems was then compared under load conditions at stock speed to the retail HSF and other recently tested CPU coolers.

X6800 Stock (2933MHz) LOAD Temperature

The Corsair Nautilus 500 and Swiftech H2O-120 Compact under load at stock speeds both reach a maximum temperature of 35C. This is one of the top performances under these conditions, but the Thermalright Ultra-120 eXtreme (32C), Ultra-120 (33C), and Tuniq Tower 120 (34C) all do a bit better in this test. The Thermalright Ultima-90 with an S-FLEX 120 fan matches the 35C as does the Scythe Ninja Plus B with a SilenX IXTREMA fan. This compares to the stock Intel air cooler at 56C under load.

It was really expected that the water coolers would outperform the best air coolers under load, since they can theoretically dissipate more wattage. The water cooling performance is still excellent under load, but a few top air coolers do even better than water cooling.

Intel P35 Load Stock Speed - Temperature in Degrees Celsius
Swiftech H2O - TAT 40
Swiftech H2O - CoreTemp 37
Corsair Nautilus 500 - TAT 40
Corsair Nautilus 500 - CoreTemp 37

The temperature pattern with TAT and CoreTemp on the P35 is a bit different under load conditions than Idle. All four results are higher (poorer) than the NVIDIA Monitor results on the 680i. CoreTemp results under the same test conditions are a couple of degrees higher than NVIDIA Monitor, while TAT results were a surprising 5C higher with both water cooling systems compared to the same system test results measured with NVIDIA Monitor.

The purpose of these comparisons of the same tests measured using three different core temperature utilities is to get a better understanding of how each program compares in temperature measurement under different test conditions. This will hopefully provide the insight needed to select a standardized program for temperature measurements on our new cooling test bed.

New CPU Cooling Test Configuration Noise
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  • EODetroit - Tuesday, September 18, 2007 - link

    The above is the best comment here. In the end, its all about heat radiation. If the air coolers have a better means for radiating heat than the water coolers, they'll win. Water usually did well because it radiated the heat outside the case and most importantly, they could have bigger radiators than the little HS&F inside the case.

    With the modern high end air coolers, the radiators are huge (even if they're inside the relatively hot case). With the water cooler setups you tested, the radiators are small (small for a water radiator, even if its radiating to the outside air). Therefore you don't really need to see the numbers to know what the result will be.

    To take advantage of water cooling, you need a big time radiator on the outside of the case... preferably with large fans that can push a lot of air through them without making a lot of noise. By testing radiators the size of a 120mm fan, you negate water cooling's biggest advantage.
  • Lem - Wednesday, September 19, 2007 - link

    I kinda agree but...

    I somewhat disagree with the reasoning because heatpipes transfer heat a lot better than the water tubes we see used with water cooling systems.

    The only benefit of water cooling is basically the fact that you can transfer heat longer distances. This allows you to take advatage of big external heat sinks.

    If there were long and flexible heatpipes out there, we would not even consider water.
  • GhandiInstinct - Monday, September 17, 2007 - link

    We need more important articles like these, as well as DDR2 comparisons and GPU comparisons....

    Anyway, I have one minor complaint, I wish the line graphs would be done away with as well as maybe labeling the names with a (AIR) and (WATER) so we know which performs best :)

    (It's very hard to tell with the line graph)
  • Jethrodood - Monday, September 17, 2007 - link

    I cant believe such a long standing tech site would draw such naive conclusions in the realm of cpu cooling. /scratches head..
  • JAG87 - Monday, September 17, 2007 - link

    This has to be one of the worst articles ever. It was decent until the very last page, where conclusions are drawn based on two cheap beginner water cooling kits, and one test platform.

    First, don't say water cooling is bad when testing beginner All-in-one test kits. These are cheap, and they perform as much as they cost.

    And second, try keeping an over clocked quad core below 60c at load with air cooling. Take a 3.6 to 4 Ghz quad, thats 200W of heat. Try cooling that with air, just try.

    And you don't have to spend more than 300 for water cooling to beat air cooling. Example: Apogee GTX/Dtek Fuzion + MCR220/MCR320 + MCP655 + MCRES MICRO + 7/16ID tubing + a few zip ties = way less than 300 dollars.

    Why don't you split your review into pricing categories, and then you can draw a conclusion for each price category, instead of calling shens on water cooling. Make a sub 200 dollar section, a 200-300 dollar section, and a 300+ section, and run tests for each. Then you can say, hey sub 200 kits are a waste of money, 200-300 kits are the sweet spot for CPU cooling, and 300+ kits are only for people who wish to water cool more than just the CPU.

    Come on Wesley, we expect better from Anandtech.
  • oopyseohs - Monday, September 17, 2007 - link

    And second, try keeping an over clocked quad core below 60c at load with air cooling. Take a 3.6 to 4 Ghz quad, thats 200W of heat. Try cooling that with air, just try.

    QFT

    I am by no means an advocate of water cooling, but I do appreciate the ability of water cooling to dissipate greater quantities of heat faster than air cooling. Maybe not faster (which is why you're getting better scores on a low TDP X6800), but more. I have tested the H20-120 Compact on QX6850's with Gabe and it's superiority to even the best air coolers is quite evident - even though it has just a single 120mm radiator.

    While I don't think this is "one of the worst AnandTech articles ever", as a previous poster so delicately put it, I think it does bring to light an important flaw in your testing methodology for coolers: that the Core 2 Duo just does not generate anywhere near the heat of the increasingly-common Core 2 Quad.
  • strikeback03 - Wednesday, September 19, 2007 - link

    I'm currently typing on a system with a Q6600 on an MSI P35 Platinum board with the jumpers set to the 333 bus speed, giving a 3.0GHz quad core. Tuniq tower at around 1400RPM, running quad Prime95 Speedfan shows core temps in the mid 50*C range.
  • rallycobra - Monday, September 17, 2007 - link

    does anyone have actual temp data to support this? At some point does the aircooling show a non linear response to additional heat and the temp shoots much higher than water cooling? I'm not sure how this is possible.
  • rallycobra - Monday, September 17, 2007 - link

    I disagree. This is an excellent article. An $80 Thermalright 120 ultra has better thermals/noise/cost/install. And no chance of a catastrophy with fluid! If the data is reliable, and I believe it is, there is no sense in anyone spending $150 on either of these kits.

    I was thinking of getting the swiftech kit, since other reviews from less credible sources said it was better than any air solution, and then upgrading the radiator to a thermochill 120.3 and keeping the apogee drive. That is a $150 radiator with a $100 cpu block/pump.

    It appears to me that you need to budget about $300 for fluid to be better than air. If you are going to go through the effort, go big or don't bother. I'm talking a huge radiator. If swiftech releases a kit with a 120.2 radiator for the same price, that may make sense.
  • Calin - Monday, September 17, 2007 - link

    Because this was a review of a pre-made, as-sold water cooling setup. You mentioned he compared installation time with the air coolers?
    The $50 and 15 minutes of installation for a top-end air cooler, compared to the hassle of buying all the afore-mentioned components and fitting them, for a $300 price point (maybe?)
    I'd say he got the right conclusion, and the article was sound. It was not intended to the water cooling experts, but to people that would (maybe) choose a somewhat simple to install $150 solution instead of a simple to install $50 solution.
    By the way, in all the list you put (Apogee GTX/Dtek Fuzion + MCR220/MCR320 + MCP655 + MCRES MICRO + 7/16ID tubing + a few zip ties), I only know for sure what zip ties are.

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