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.

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  • MercenaryForHire - Tuesday, September 18, 2007 - link

    Folks, this is a review of off-the-shelf watercooling components. Not a customized, modded, build-it-yourself Hoover Dam setup. And the conclusions drawn I think are valid - if you want good results from watercooling, be prepared to fork over some significant coin, or source the parts yourselves and DIY.
  • jebo - Tuesday, September 18, 2007 - link

    Exactly. I find it interesting how all the water coolers are crying that AT said "Air is better than water". Well, the fact remains, that if you compare a $70 air cooler to a $150 water cooler, air is > water. You need to spend $300+ to get a h2o system that is better than a $70 air cooler. At that point, the cost concerns become prohibitive.
  • psychotix11 - Tuesday, September 18, 2007 - link

    Part of the problem with this review is that it's managed to convince novice users that it does require 300+, which is either a distortion of truth to make a point, or ignorance about basic water cooling.

    Pump - 65, apogee GT - 45, double rad - 50, misc crap (tubing, fittings, fans) - 20.

    For exactly around 200 bucks you can construct a loop that will demolish any air cooling on the market. You could even toss another radiator into the swiftech kit and keep it under 200.

    For 300 bucks you could toss in a 3x120mm rad, upgrade the CPU block, and liquid cool the NB and go even farther.

    For a 300+ configuration the sky is the limit.

    Also I've noticed the numbers they get don't match what other reviews have put out for a lot of the items used.
  • Nickel020 - Tuesday, September 18, 2007 - link

    As aigormola stated, ~200$ watercooling setups will beat any air cooling. A dual radiator doubles the heat dissipation capacity and is like 10$ more than a single.
    And don't forget that you can keep you watercooling setup for like 5 years, while you usually get one 50-80$ heatsink and fan every time you upgrade your PC.

    The review is fine, but the conclusion is the worst one I've seen in 5 years of reading reviews at AT. It's just plain wrong and will mislead a lot of people.
  • aigomorla - Monday, September 17, 2007 - link

    First off, your picking the subject area which holds the most debate. Its a common ground fact that a 120x1 radiator will be lacking. Your test subjects were in fact both 120x1 radiators. One was made of ALU and the other Copper.

    Your looking at entry lvl water cooling and using it as a comparison of middle class custom setups.

    If you look at the swiftech APEX 220 series, you'll see your statement at the end not hold true.

    The direct drive released by swiftech on a 120x1 platform, as well as the corsair nautilus is not the best grounds to claim such statements. The reason is the lack of the radiator.

    120x2 radiator setups such as the swiftech Apex220 setup will eat the two coolers you listed and also any air setup you could possible throw. This unit is also modestly a bit over 200 dollars. Last price checked at jab-tech showed it to be 209 dollars for the complete setup.

    Also your making a lot of potential people who are interested in h2o migration think twice. Your passing more myths on watercooling then i can think of. If you feel i am wrong in any statement, i recomend you contact Gabe, owner of swiftech and tell him you would like to give the company a chance to prove how powerful h2o cooling can be by giving you a sample of there APEX 220 system. Im sure Gabe will be all over it.

    Also, you need to retract your statement about the 300 dollar mark. 200-300 is considered mid tier water cooling and no air can match to that calibur.

    @ the guy who was about to migrate to the MCR320. Go ahead, and dont look back. This review only proved the power of 120x1 radiator. Its very lacking, however the moment you step up to a beefier radiator, 120x2 or 120x3 in your case, you'll see all the air people left behind in your rear view mirror. 2x the cooling power for the 220, and 3x the cooling for the 320.

    Lets not even get into the power of a thermochill PA120.3 Believe me, its a very very big margin once you get there.

    I am the creator of the watercooling thread sticky over at anandtech forums, and i was VERY disappointed in this article. The members over at Xtremesystems think this is a joke. These are the guys who are the front run pioneers in h2o cooling.

    I ask polietly that you remove that comment of the 300 dollar being topped by high end air until you've tested an APEX 220 unit. All you have done was test 2 low end units in h2o and based a final conclusion.
  • walltari - Tuesday, September 18, 2007 - link

    Very interesting review a pretty tough discussion but everybody forget one thing. You look only on very expensive kits useally common in U.S. or western Europe. I live in Czech republic (Eastern Europe) and I see another choises. I have completly watercooled PC. Radiator 2x120, pump with expansion and filling tank, CPU blok, GPU blok, Chipset blok, 2x HDD blok a this kit i bought for 210$. In this price you coudn´t buy ale these aircoolers and have same results. (I bought it form company www.viscool.com). I hear, and that´s the problem, that everybody have, DVD-rom.

    In the review author hit the problem of the noise. Really the pump is the most noisest thing. I´m interested in building watercooled systems for three years and at first it is neceseary eliminate vibrations. The differnce is that my system and systems of this firm is waterpump included in watertank. This solutions lower noise to minimum level. They have 2 watertanks, one, included in kit, is smaller and second, which they made especially for me, because o my larger and more powerfull pump.

    PS: Sorry for my english, I´m beginer
  • rotNdude - Monday, September 17, 2007 - link

    Which direction was the fan blowing on the Swiftech kit? Since you mounted the rad off the back of the case and the fan appeared to be in the case, was it exhausting air or pulling ambient air?

    Also, how much fluid was actually added to each cooling loop?

  • Wesley Fink - Monday, September 17, 2007 - link

    We used the existing case fan IN the case exhausting air. We also used the fan that came in the H2O-120 kit blowing air in the same direction. There is a 1-1/2" to 2" space created by the Radbox so air was being drawn in form the sides of the rad box.

    The pre-cut tubing in the Swiftech kit is about 10" long each. We used 12" tubes to reach the external RadBox mounted Readiator/Reservoir.
  • Jodiuh - Monday, September 17, 2007 - link

    Thank you guys very much for using this universally accepted tool. I've always wondered why the temps for Thermalright's Ultra 120 Extreme were better than what I could achieve. There's 4 factors here:

    -ambient (20C-22C vs 24C-26C)
    -temp monitor (NV vs core temp)
    -fan (1600RPM vs 1200RPM)
    -load app (farcry vs orthos blend) <--this might not matter

    I'm currently loading an E6400@3500 between 62C-66C w/ 1.475 in bios (1.43 actual) when running orthos blend.

    Thanks again! Maybe orthos blend could be used in future or even ran again on past coolers?
  • rochlin - Monday, September 17, 2007 - link

    These results totally make sense if the laws of physics have anything to do with it.
    There are some advantages to water cooling vs air, but you have to take advantage of them:
    Heat dissipation and the high specific heat of water: Because the dissipation of heat is separated from the CPU, you can have a bigger and more efficient heat sink than you can ever fit on top of a cpu.

    Also, because the heat dissipation (heat sink) is outside of the case, you can use the presumably cooler air outside the case to cool the heatsink.

    The point is, the water needs to be cooled. If the heat sink/fan setup cooling the water is no better than what you attach to your cpu, then the system will NOT cool your cpu any better. You will be recirculating relatively warm water back to the cpu.

    A sensible approach would be to build a giant heat sink. It could be aluminum (cheap) and big enough so the WHOLE case could sit on top of it. A channel for the water would zig zag under it. This kind of heat exchanger (like used in solar water systems) would cool the water much much more than anything you could fit inside the case.

    The relatively small heat exchangers in the two tested units just aren't going to outperform the terrific Themalright 120 Extreme heatexchanger unless your air temps inside the case get out of hand. The advantage of the heat transfer capability of water is WASTED unless you cool it down with a better heat exchanger outside the case.

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