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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  • rallycobra - Monday, September 17, 2007 - link

    I'm building a new quad system, and I was going to go with the swiftech kit, and upgrade to a 120x3 radiator in the future. For now, I'm going to stick to air.

    Can you run the test again with a quad? Another site says that the swiftech outperforms all air solutions, but I trust your methodology a lot more.

    Watercooling is elegant if you have the radiator outside the case, and you can cool the cpu, chipset and vga. It keeps the inside cool, and gets all of the heat out.

  • aigomorla - Monday, September 17, 2007 - link

    Your upgrading to 3x the cooling power this article previewed.

    So if there saying a 120x1 will match a ultra120extreme, your saying 3x that cooling power isnt worth the migration.

    *scratches my head*

    This is what i mean about this article screwing people up in water migration.
  • poisondeathray - Monday, September 17, 2007 - link

    Thanks for the interesting review.

    Given the increasing prevalence of quad-cores, it might be interesting to repeat the tests with an overclocked quad core configuration.

    Although the testbed was different, at least 1 other hardware site got better results with similar watercooling vs. Tuniq.
  • gingerstewart55 - Monday, September 17, 2007 - link

    I wonder what was wrong with your setups and your pumps. Having had the Corsair Nautilus 500 unit, and the pump the Swiftech kit is based upon, something is/was seriously wrong with your setup or pumps.

    The Corsair unit's fan, at least in the one I used, drowned out the pump completely.

    The Laing pump in the Swiftech kit, the same pump in the Corsair kit by the way, is sitting in my computer and is utterly silent....completely drowned out by any of the four fans in the case....three Scythe S-Flex "E" fans, at 22 dBA on full speed, and an Antec SpotCooler on lowest speed (the Antec is the loudest fan in the case, btw.)

    I'd almost hazard a guess that both kits, after being set up, still had a bubble/pocket of air in the pump. The Laing pump can get quite noisy if no completely bled of air.

    Otherwise, there was a mechanical fault in both your kits' pumps as the Laing is almost completely silent when working as attested to by the hundreds of people using those pumps and hearing absolutely nothing from them when being used.

  • Nickel020 - Monday, September 17, 2007 - link

    You need at mod top for the Laing pump, it's unbearable without one, but if decoupled almost unhearable with a good top.
  • Wesley Fink - Monday, September 17, 2007 - link

    We tested both systems as provided by Swiftech and Corsair. Both units are provided as complete kits and both manufacturers are familiar with our cooler test methods.

    Modding everything we test defeats the purpose of our comparative testing.

    We are not finished with water cooling reviews, and we will be reviewing more water cooling systems in the future.
  • Nickel020 - Monday, September 17, 2007 - link

    That's not hwo I meant it, of course you shouldn't mod the kits for testing. I was just saying that the Laing is not a bad pump for custom setups, in fact, it's pretty much the best pump for most setups if you use a mod top, which makes a big difference. I don't think I've ever seen a pic om someone using it without a mod top, but dozens with all kinds of mod tops.
  • Wesley Fink - Monday, September 17, 2007 - link

    I first thought there was a pump defect as well. So I acquired FIVE Apogee drive blocks from different sources and all measured similar dbA noise levels. There was also the 6th pump in the Corsair Nautilus 500.

    Subjectively the pumps were relatively quiet because the noise frequencies appear to fall in a freqency range that is not particularly annoying. However, our standard sound meter said measured noise was pretty high. We stated this in the review and also commented the pump noise was not annoying to our ears, but it may be to others. Measure the noise of your system and let us know what you find.
  • psychotix11 - Monday, September 17, 2007 - link

    These two set-ups do not represent the top end of water cooling. It's long been past the point where a single 120mm rad is enough for a CPU.

    Toss these out and replace them with a custom set up with a dtek fuzion CPU block, 2x 120mm fan rad, ddc pump with petras top, and 1/2 id tubing and then see where it gets you.

    Also liquid cool the chipset and then see if stock air can keep up (after), it won't.

    You're taking two premade kits made for the user that has never water cooled before. It's simply not in the same category as the higher end custom kits.
  • Wesley Fink - Monday, September 17, 2007 - link

    We did not state water cooling was always inferior to the top air coolers. We said, based on these test results and others we have run recently, that you would need to spend more than $300 on a water cooling system that might outperform the best air coolers.

    At more than 4 to 6 times the price of a top air cooler most readers would not conseder that good value.

    I actually agree with your comments, but please tell us the total cost of the water cooling setup you say is needed to beat the best air coolers.

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