Final Words

"Conventional wisdom" tells us that water cooling systems will always cool better than air coolers and water coolers will always be lower noise than the best air coolers. Any computer enthusiast has heard this ad nauseum and probably repeated these "truths" to their friends. Unfortunately these conventional wisdom maxims were coined a few years ago when air coolers were heavy blocks of copper, heatpipes weren't used on coolers, and the cooling fans were small, high-pitched screamers.

Whether everyone has noticed it or not, air coolers have been undergoing a revolution since these maxims were genuine truths. Fast forward to today and you will find the heatpipe tower the dominant design for top air cooling. The liquid-filled heatpipes provide many of the benefits of conventional water cooling and the fan most often paired with these heatpipe towers is a side-blowing, rear-facing 120mm fan with high output combined with low noise.

With these developments firmly in mind it was time to put "conventional wisdom" under the microscope again. The worthy test subjects for examining these water cooling "truths" are the Corsair Nautilus 500 external water cooling system and the Swiftech H2O-120 Compact. Both these water cooling systems are also the beneficiaries of the evolutionary development of water cooling since they both combine top water cooling components in simpler to install water cooling kits. They are also reasonable as water cooling kits are concerned, at around $130 to $150. However, even at these excellent prices the water cooling kits are two to three times the price of the top air coolers.

The cooling tests are now complete and it is time to look at each area where water cooling was considered superior to answer whether water cooling is still better than air.

Cooling Performance: Both the Corsair and Swiftech water coolers mirror the second tier of air coolers in cooling efficiency. They match the best air coolers we have tested at stock idle only. At all other speeds and load conditions the top three or four air coolers out-cooled water.

Overclocking: Seven air coolers tested by AnandTech overclock higher than the Swiftech H2O-120 Compact and the Corsair Nautilus 500. The Thermalright designs do use the convex (bowed) base plate which has been shown to increase cooling by 2C to 3C and therefore increase overclocks. Swiftech has been shipping bowed base plates on their top water blocks and they will add the bowed base to the H2O-120 Compact. That may improve performance of the Swiftech water system to near parity with the top air coolers. The operative term is near parity. We have yet to test a water kit below $300 cost that can match or outperform a top $50 to $75 air cooler.

Noise: The Swiftech and Corsair water systems were noisier than almost any air system we have tested. With air coolers the noise can only come from the fan and most fans can be replaced with a quiet, high-output fan. Noise from the H2O-120 Compact and Nautilus 500 water systems is mostly from the buzzing and humming of the water pump and it is not easily corrected. Subjectively the water cooling noise, while measuring high, is not particularly annoying in frequency. Many users will find it easy to live with. In this regard the Swiftech has the greatest potential for damping noise since the water pump is inside the case where the Corsair mounts the water pump outside the case.

Flexibility: Water cooling enthusiasts rightly point out that you can effectively cool hot VGA cards by just adding a VGA block to your water system. Or tame a hot chipset with a chipset block. That is true, and even these reasonable kits offer the option of driving additional VGA and system cooling blocks. Air can never offer this level of flexibility, but the cost will be higher than you expect and it might be cheaper to buy one of the new self-contained water-cooled VGA cards to use with your top-performing air cooler. Scaling of water cooling performance when it has to deal with GPUs and chipsets as well as the CPU is also something that needs to be considered.

Finally, there are two areas where air cooling is considered the superior solution. Do comparisons still show air to be superior to water in these areas?

Ease of Installation: In general air cooling is a much simpler installation. Also, if you're sloppy in an air installation your system might shut down so you can correct the problem. If you're sloppy with a water cooling installation your board may be fried. The two water systems tested here were designed for easier water installation. With the right case the Swiftech is fairly easy, but it is quite complicated if you plan to use it in a common top-mounted PSU mid-tower case and extra parts are required. The Corsair is an extremely easy install that works in every case we have available for testing. It's so easy it will take less time to install than top air coolers that require a motherboard removal to install the air cooler.

Value: Water cooling systems have been dropping in price while the prices for top air coolers have been increasing. Still any water cooling system that even has a chance to compete in performance with the top air coolers will cost $130 to $300 for the kit. Top air coolers cost $50 to $75. At one half to one sixth the price top air cooling is still a very good value by comparison.

The Bottom Line

The next time a computer friend tells you water cooling performs better or is quieter than air cooling, tell him his information is out of date. Air coolers have evolved to the point where a top $50 to $75 air cooler will normally outperform a water cooling kit at $300 or below. The best air coolers are much cheaper, easier to install, lower in noise, and provide better overclocking results than water cooling kits that are up to six times more expensive.

However, water cooling is still very desirable if you also want to cool a hot video card or a hot chipset, since almost every available water cooling kit allows the easy addition of VGA and chipset blocks. For many this one feature, the flexibility of additional water blocks, is reason enough to run water instead.

Our tests of the "Easier to Install" Corsair Nautilus 500 and Swiftech H2O-120 Compact show both systems to be worthy competitors at their price points. Both systems cool to levels just below the top air coolers, and both facilitate overclocks just below the top air coolers. Neither water system, however, can match the performance of the top seven or eight air coolers tested at AnandTech, which sell for one third to one half the price of either the Swiftech or Corsair water cooling kit.

If your planned install is a full tower case or a mid-tower with a bottom mount power supply then either the Corsair or Swiftech will be easy to install, with the Swiftech offering more flexibility in controlling water pump noise. If you plan to install in a more common top-mounted PSU mid-tower case the Corsair Nautilus 500 is the better choice, since the Swiftech will require additional parts for an external of split install.

In the end the only persuasive reason to buy a sub $300 water cooling system is if you want to add VGA and/or chipset cooling. There seems to be a trend by some enthusiasts to put together extremely large water cooling systems with multiple large banks of radiators and cooling fans. Some featured at enthusiast sites look more like car radiators than computer water cooling systems. These systems can undoubtedly cool better than a $50 to $75 top air cooler but they also cost substantially more than $300. You have to spend more than $300 on water cooling that might outperform the best air coolers.

We asked when we started this review "Is water better?". The clear answer is NO, after comparing the Corsair Nautilus 500 and Swiftech H2O-120 Compact to the top air coolers. Water cooling comes close to top air performance in current designs but it did not outperform top air cooling in any test results. Upcoming improvements in block design may bring water performance closer to the best air coolers but water is not likely to provide better performance than air in kits priced at under $300. Air is also much quieter than these water kits. For most enthusiasts air cooling is the better value, better performer, and lower noise system. Unless you plan to also water cool your video card and/or chipset there is no real reason to buy water cooling instead.

Overclocking
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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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