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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  • geok1ng - Wednesday, July 23, 2008 - link

    There is no reason to dump $120+ on a budget water cooling system for CPUs since most sub$50 air coolers will do a good job

    but with SLI/crossfire systems the typical air cooling solution are suboptimal to say the least. Even you have a board that can fit 2 VGA and 2 Acellero S1s, there is no way to put good airflow averthe humungous setup!

    Someone plaese give us a water cooling solution for multi GPU systems that doesnt cost MORE than the VGAs!
  • Cregaune - Tuesday, March 25, 2008 - link

    This review has given me lots of food for thought. Frankly, I find the conclusion incredible.

    Perhaps you guys are right, but before people jump to your conclusions I wonder why your ambient room temps were kept within such loose margins i.e 20'C to 22'C.........a full 3'C !!!

    Controlling ambient room temperature is particularly important when reviewing a water cooled system, simply because it can take an hour or more for the coolant temperature to stabilise; before you can legitimately take a reading. If, in the meantime, you let the room temperature fluctuate within such grossly wide margins, your results are next to useless....especially given the relative performance figures in your findings.

    Just a thought!

  • Cableaddict - Friday, April 11, 2008 - link


    As far as performance goes, I'd say you present a valid argument. The specific kits you tested are not worth investing, vs a few of the best air-coolers. So far, so good, but your conclusions and general tone seem to fail badly after that one true point.

    You wrote, (in this thread) "We state you will likely need to spend more than $300 to possibly outperform current top air coolers."

    Nonsense. As many have mentioned, the big problem with these kits is the use of a single "220" size radiator. Using a dual-rad, or two singles, has been shown in test after test to increase cooling dramatically (even with a "lowly" Swiftech rad) So, one could buy the H2O-120 and add another radiator for $42 more. That's WELL under $200, and the performance OC'ed & under load will slightly outperform the Ultra-120. AND , it will be much less noisy.

    You conclusions about noise are correct, but only at lower fan speeds.You posted a chart showing high OC / high load performance, but failed to include noise specs under those conditions. The noise comparisons at lower cooling settings do not apply at all. I've been looking at TONS of tests, specifically weighing cooling vs noise. At the high speeds needed to make the Ultra-120 types perform their best (about equal to a low-end dual radiator WC) they are much, MUCH noisier than WC, according to every test I've read.

    Last: Bear in mind that many folks cannot fit those big air-coolers, espially HTPC people, or those with rack-mount music & video pc's. For such rigs, the best air coolers that will actually fit are the Gemini II, the DuOrb, etc. Even a single-rad WC setup does better than those when OC'ed & under load. (according to many tests I've seen.) With a dual-rad, WC systems decimate these air-coolers. For instance, one test put a Gemini II / dual Noctua blower against the H2O-220 kit. At 3.7 Ghz, under load, the WC was 15º cooler.


    Regarding pump noise: Well again, your comparisons are fair if one is going to strictly obey the "rules" and not mod any system at all. However, One can pretty easily add sonex or other noise absorbtion to the inside of the case, and limit a good bit of that pump noise.

    Going to a non-kit system, one can now choose the Lang D5 vario, dial it down a little, and add some sound isolation around it. Not so hard, and all reports say it is then virtually silent. With a dual-rad performance should still be excellent. Granted, that's approaching the $300 mark, but serious overclockers would certainly do better with such a set-up, and it would be LESS noisy.

    I guess one last question must be addressed, and that is: Just how cool do we need to go? Let's say one want to OC a Q6600 (timeframe of this review) to 3.8 ghz. A $75 air-cooled rig will run under heavy load at (let's say) 60º, and a decent WC rig will run it at 50º. Is 60º safe enough, day after day, that the WC system is not worth the substantial cost? I don't know the answer. I wish I did.

    -And when pushing the FSB really hard, one might worry about the rest of the mobo components. -So now we have to weight the WC advantage of being able to also cool the NB and GPU, vs the air-cooler advantage of cooling the ram,NB, mosfets, etc.
    One might reasonably say that,with heavy OC, a WC set-up requires an additional case fan, and that means a little more noise.

  • Cableaddict - Friday, April 11, 2008 - link

    Custom H2O-220 type system:

    Swiftech Apogee Drive 350 Pump / CPU water block combo $80

    Swiftech MCR220-res: $55

    2 Noctua fans: $50

    non-evaporate hoses / clamps: ~ $20 MAX.

    Hydrex: $3
    $210 or less.

    Swap-in a Lang Vario D5 pump and an Apogee or Fuzion waterblock, instead of the Apogee Drive 350, and you still under $275.

    Test either of these systems on a Q6600 @ 3.8 Ghz, against any air system, includng the Ultra-120, and then get back to me.

    Also bear in mind that either of these systems will easily also cool a GPU, with another $50 of parts.

  • Cableaddict - Saturday, April 26, 2008 - link

    One more noise consideration:

    Granted this is a review of the H2O single, but for very little more money one can get the H2O with a double rad. THAT system should slightly outcool even the ultra-120, but what;s most important is that it will be MUCH quieter.

    Again, the Ultra-120 types require pretty high CFM's to give good results. A dual radiator can deliver excellent performance with a pair of Nocyua 1300 rpm fans. That's bloody silent.
  • perfectdarth - Sunday, December 30, 2007 - link

    you cant say say that watercooling is bad because a 2 budget kits get beaten by an ultra 120. watercooling does cost more but radiators and pumps last years and for $300 (no more) you could make a custom kit that would be quite a bit better than the top air coolers when cooling an overclocked cpu.

    you harped on how watercooling costs more and takes more time/effort but you didnt state that people that are willing to spend the extra time/money dont always do it just for better temperatures and might find it fun and a bit of a challenge the first time. putting on a heatsink isnt very satisfying, you could train a monkey to do that. you could say people who spend $800 on a graphics card to play games at max are stupid because its still the same game at medium on a $350 graphics card but if you like to lay games that look nice you would think its worth it, it was like you had your mind made up before you wrote this article

    people saying that the hassle of watercooling isnt worth it is just plain ignorance, some people enjoy maintaning their car themselves but other people would go meh and go pay someone to check their oil and water. that doesnt mean that people who dont care should tell the people that do it themselves that they are wasting time or the they should tell the lazy ones they shouldnt be lazy. watercooling is a hobby just as much as it is a way to better cool your computer.

    i would like to see the swiftech h20-220 Apex Ultra tested against the top aircoolers since it is a very good kit and under $300 afaik. also watercooling seems to make a much bigger difference to graphics cards than cpus.

    saying that you would rather buy a phase change over a good watercooling kit is rediculous. phase is more work and just as if not more risky than watercooling because of condensation.

    also why farcry and not use tat or orthos? i didnt like this article much since it is very bias towards air. i read "water is useless air is so much better" all the way through.
  • rabident - Tuesday, September 25, 2007 - link

    You could argue heatpipe coolers are closer to water coolers than air coolers. They're basically sealed water coolers. Most use distilled water as the heat transfer medium, just like conventional after coolers, except heat pipes are more efficient because they involve a phase change (which absorbs a lot of heat).

    The real value with conventional watercooling is the freedom to piece together a custom cooling system that meets your needs. It lets you balance price, cooling performance, and noise the way you see fit. Plus there's a lot of room for creativity.

    I think it's going be hard for water to beat air in price/performance, but if price is the #1 factor then I think the value of any after market coolers is questionable.
  • Starglider - Sunday, September 23, 2007 - link

    This review is ok, nothing amazing but the accusations being thrown around seem unwarranted. However the basic conclusion is this; modern heatsinks are good enough that for a single medium-speed 120mm fan, cooling is airflow and radiator surface limited. With heatpipes and improved layout heatsink thermal conductivity is no longer an issue (for quality air coolers).

    It would be nice if this was made more explict in the conclusions, and I am dubious about the claim that you can't get a better radiator solution (e.g. dual-120mm or reserator) for under $200. The notion that water cooling won't give you any advantage other than chipset/GPU cooling is false in the general case; it is only true if you have a single 120mm fan radiator (plus it ignores the benefit of lowing case internal temps).
  • strikeback03 - Wednesday, September 19, 2007 - link

    So is the "water additive" really just old-school green automotive coolant, i.e. ethylene glycol? Or does it just look that way?
  • aigomorla - Tuesday, September 18, 2007 - link">

    Sorry. This review was better writen. And shows this cooler clearly owning air.

    The editor i feel now has a grudge against water cooling. He is pushing air is greater then water when it looks like he has no experience with a decient water setup.

    The pump making a lot of noise? Okey, can one owner who has a DDC confirm this? Because i have 4 and none of them make loud noises.

    The Liang D5 doesnt even make loud noise, and its a bigger pump.

    Sorry your 300+ watercooling comment needed to beat air... thats absolute BS.

    People please do some research b4 you buy into this review. I asked the editor polietly to remove that statement and he has yet to remove it. I ask you guys to check out our case and cooling forum. There is a post on this and listen to what all the members on AT are saying. Only the editot of this article believes in his 300+ needed to beat air. The rest of the members on board totally disagree with him. XS is laughing at anandtech at the moment. Even the air cooling people at XS are laughing because its a KNOWN FACT a 120x2 radiator would demolish anything AIR can bring up. Even TEC air coolers dont stand a chance.

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