Noise

Everyone "knows" that water cooling is quieter than air cooling. We have been told that for years - so much so that many enthusiasts no longer question this idea. That is certainly true when comparing water cooling to the small, loud fans on air coolers of the past. However, the current top heatpipe towers use large, high-output, low-noise fans for cooling and it is time again to challenge conventional wisdom based on out-of-date "facts".

For many enthusiasts upgrading cooling, the goal is maximum stable overclock, and they will live with the inconvenience of a louder system. For other users silence is the most important factor, and these users will forgo maximum overclocking if that increases system noise levels. That is why many who value silence choose water cooling.

Noise Level - 6

Noise Level - 24

The belief was that water cooling noise levels would be so low that pages would be required to detail the lower noise levels of our new cooler test bed in complete detail. Once again we're totally shocked that these two cooling kits from major players using top water cooling components are among the noisiest cooling systems tested so far at AnandTech.

Assuming something must be wrong with our results or the 120mm fans in the water cooling kits, we tested many times and got the same results. Where then, does the 45-46 dB(A) noise come from at 24", when the system noise floor is 38.3 dB(A) on the old test bed and much lower on the new cooling test bed? What is generating the 52.3 to 52.5 dB(A) noise at 6" where the system noise floor is worst case 47 dB(A) and the new test bed is even lower?

It turns out the noise culprit is the water pump on both systems. Measured noise at 24" with the pump and fan running was around 46 dB(A) on the Swiftech, where noise level with the pump only and the fan disconnected for a short time was 45.5 dB(A). Results with the Nautilus were similar, proving the offender in noise is the water pump. With pump noise so high it was pointless to test the fan at lower voltage since it was only adding 0.5 dB(A) at full speed and highest noise.

It is very important, however, to talk about perceived noise. The water coolers measure very high noise levels, but the noise frequencies are not particularly irritating. The pump noise is a low hum instead of a high-pitched scream and most users would rate the noise as audible, but not particularly annoying.

There is also the comparison of the internal mount water pump on the Swiftech H2O-120 Compact and the external mount water pump on the Corsair Nautilus 500. Our test method with the open case side is the worst possible noise you can get with the Swiftech. If you close the case side the noise drops about 5 dB(A) with the Swiftech, which is much quieter but not silent or competitive with the best heatpipe towers using high-output low noise fans. The Corsair external cooler noise, on the other hand, is what you get. There are no noise producers inside the case that can be damped with a Corsair external water cooler install.

Cooling at Stock Speed Scaling of Cooling Performance
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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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