Closed Loop AIO Liquid Coolers: 14-way Mega Roundup Review
by E. Fylladitakis on February 12, 2014 7:00 AM ESTTesting Methodology
Although the testing of a cooler appears to be a simple task, that could not be much further from the truth. Proper thermal testing cannot be performed with a cooler mounted on a single chip, for multiple reasons. Some of these reasons include the instability of the thermal load and the inability to fully control and/or monitor it, as well as the inaccuracy of the chip-integrated sensors. It is also impossible to compare results taken on different chips, let alone entirely different systems, which is a great problem when testing computer coolers, as the hardware changes every several months. Finally, testing a cooler on a typical system prevents the tester from assessing the most vital characteristic of a cooler, its absolute thermal resistance.
The absolute thermal resistance defines the absolute performance of a heatsink by indicating the temperature rise per unit of power, in our case in degrees Celsius per Watt (°C/W). In layman's terms, if the thermal resistance of a heatsink is known, the user can assess the highest possible temperature rise of a chip over ambient by simply multiplying the maximum thermal design power (TDP) rating of the chip with it. Extracting the absolute thermal resistance of a cooler however is no simple task, as the load has to be perfectly even, with the ability to vary the load, as the thermal resistance also varies depending on the magnitude of the thermal load. Therefore, even if it were possible to assess the thermal resistance of a cooler while it is mounted on a working chip, it would not suffice, as a large change of the thermal load can yield very different results.
Appropriate thermal testing requires the creation of a proper testing station and the use of laboratory-grade equipment. Therefore, we created a thermal testing platform with a fully controllable thermal energy source that may be used to test any kind of cooler, regardless of its design or compatibility. The thermal cartridge inside the core of our testing station can have its power adjusted between 60W and 340W, in 2W increments (and it never throttles). Furthermore, monitoring and logging of the testing process via software minimizes the possibility of human errors during testing. A multifunction data acquisition module (DAQ) is responsible for the automatic or the manual control of the testing equipment, the acquisition of the ambient and in-core temperatures via PT100 sensors, the logging of the test results, and the mathematical extraction of performance figures.
Finally, as noise measurements are a bit tricky, we're measuring these manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is acquired via a laser tachometer. The fans (and pumps, when applicable) are powered via an adjustable, fanless desktop DC power supply and noise measurements are being taken 1m away from the cooler, in a straight line ahead from its fan engine. At this point we should also note that the decibel scale is logarithmic, which means that roughly every 3 dB(A) the sound pressure doubles. Therefore, the difference of sound pressure between 30 dB(A) and 60 dB(A) is not "twice as much" but nearly a thousand times greater. The table below should help you cross-reference our test results with real-life situations.
| Noise Level Reference Values | |
| <35dB(A) | Virtually inaudible |
| 35-38dB(A) | Very quiet (whisper) |
| 38-40dB(A) | Quiet (slight humming) |
| 40-44dB(A) | Normal (humming noise, comfortable level) |
| 44-47dB(A) | Loud* (strong aerodynamic noise) |
| 47-50dB(A) | Very loud (strong whining noise) |
| 50-54dB(A) | Extremely loud (level equivalent to a ≈1500W vacuum cleaner) |
| >54dB(A) * | Intolerable for home/office use; special applications only. |
* Noise levels above this are not suggested for daily use
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E.Fyll - Wednesday, February 12, 2014 - link
I do not like listing "winners", giving ratings and stuff like that. From a pure performance point of view, perhaps you are right. The H110 will not fit in a case however that can only take 280 mm long radiators. It may be too expensive for some. Too ugly for others. Too black. Even too mainstream (yes, there are people who think like that).I hate ratings because they are subjective and misleading. It reminds me exactly of that:
http://i.imgur.com/B5TgS.jpg
If I give a good rating on three products for entirely different reasons, that does not mean that they are anywhere near the same or meant for the same groups of users. Yet, most people would only check the rating and think that they are similar. Furthermore, just because I gave a product a good rating, that does not make it good for everyone; it could be entirely useless to certain people and target groups. As I said before, I am not fond of basing any part of a review on subjective elements and I despise the very idea of imposing my thoughts to others.
How about I stick to testing and writing and you (the readers) give the ratings you think each product deserves? :)
The PC Apologist - Wednesday, February 12, 2014 - link
From the AnandTech About page, under Review Philosophies:"Our reviews incorporate a mixture of objective and subjective based analysis, the balance varying where appropriate. We are not a site that exclusively relies on data based comparisons but also deliver honest user experience evaluations as well. Some reviews lend themselves to data driven analysis more than others (e.g. CPU review vs. smartphone review), but we always attempt to provide both in our coverage. I fundamentally believe that you need both to accurately portray any product. Numbers are great for comparative analysis, but without context they can be meaningless. Similarly, personal opinions are great to help explain what owning a product may be like, but without data to back up some claims the review lacks authority (e.g. average vs. good battery life begs to be quantified)."
E.Fyll - Thursday, February 13, 2014 - link
True. However, that text also describes the philosophy behind articles that belong in dozens of different categories.My objective analysis relies on testing and data. My professional opinion lies on the description of the product, its quality, flaws and uses. I can and do comment on the design and appearance. However, whether it is beautiful/useful for you or not, I believe that you can decide that for yourself, you do not need me to tell you that. :)
That being said, subjective opinions are extremely useful in other articles, but in a cooler review they are nothing sort of useless to the end reader. My personal preferences and tastes are of no use to anyone but myself. So, you can possibly say that my subjective opinion about my articles is that you can make up your own mind. ;)
Sushisamurai - Thursday, February 13, 2014 - link
Agreed. I'd buy a NZXT case vs a better case (thermal and sound performance) at a higher price, for many "irrational" reasons: my wife thinks black matches the decor of the room, and aesthetically, it may look nicer. Is it the best in terms cost and time efficiency? Hardly, but the utility I get from a happy wife is more than enough to make up for it.Sushisamurai - Thursday, February 13, 2014 - link
And... Even though some AIO coolers may perform better, sometimes the wife just wants matching logos and parts. ...so thank you Anandtech and your wonderful reviewsThe PC Apologist - Thursday, February 13, 2014 - link
I think you may be onto something there, something big.The objective vs. subjective struggle is extremely related to what I plan to offer AnandTech.
But such a challenge is no easy task, which is why I will only submit my work after much thought and deliberation.
zlandar - Wednesday, February 12, 2014 - link
Really well done and thorough roundup.killer14 - Thursday, February 13, 2014 - link
no swiftech sets.. to bad...killer14 - Thursday, February 13, 2014 - link
to bad no swiftech sets where tested, like the H220coachingjoy - Thursday, February 13, 2014 - link
Great topic, good job.Validates my usage of Corsair products.
In the minds eye H90 would work better than thinner solutions.
It does! Good for Corsair.
Thanks