Testing 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, steady and variable, as the thermal resistance also varies depending on the magnitude of the thermal load. Therefore, even if it would be 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 much 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 and or compatibility. The thermal cartridge inside the core of our testing station can have its power adjusted between 60 W and 340 W, in 2 W 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 the 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, their measurement is being performed manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is being recorded via a laser tachometer. The fans (and pumps, when applicable) are being powered via an adjustable, fanless desktop DC power supply and noise measurements are being taken 1 meter 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.

The noise floor of our recording equipment is 30.2-30.4 dB(A), which represents a medium-sized room without any active noise sources. All of our acoustic testing takes place during night hours, minimizing the possibility of external disruptions.

<35dB(A) Virtually inaudible
35-38dB(A) Very quiet (whisper-slight humming)
38-40dB(A) Quiet (relatively comfortable - humming)
40-44dB(A) Normal (humming noise, above comfortable for a large % of users)
44-47dB(A)* Loud* (strong aerodynamic noise)
47-50dB(A) Very loud (strong whining noise)
50-54dB(A) Extremely loud (painfully distracting for the vast majority of users)
>54dB(A) Intolerable for home/office use, special applications only.

*noise levels above this are not suggested for daily use

The SilverStone Permafrost Series AIO Coolers Testing Results, Maximum Fan Speed


View All Comments

  • BenSkywalker - Friday, June 19, 2020 - link

    I don't look at the names of posters, I look at the message they posted. You chose to post in the comments thread on an article about an add in water cooler to spread misinformation and FUD. People who use water only do so once? I haven't met a single person, ever, who falls into that category.

    Water runs cooler and it is quieter while being more expensive. That is a factual statement.

    You take exception to the facts and imply some level of emotion to be at play.... bizarre.

    Water cooling is a frivolity, as is the process of building a computer in the first place. This article is about a component used in building a computer, a certain level of frivolity should be self evident.
  • PeachNCream - Saturday, June 20, 2020 - link

    What misinformation and FUD are you talking about? You're still trying to demonize the person behind a message you dislike by making accusations that aren't supported in the very text you are responding to because you feel threatened over something you bought for your personal enjoyment. That's rather - I guess the best way to express it is to simply say that's young and lacking in life experience. Reply
  • BenSkywalker - Saturday, June 20, 2020 - link

    Would air coolers paint these in a poor light...

    Two seconds to prove that implication absolutely wrong.

    Most people only go water once

    This isn't quite so fast, but any time spent on enthusiast forums will show you that certainly isn't true.

    Air cooling is more that enough ...

    10900K would line to have a word.

    We don't have a large enough sample size to know how common leaks are.....

    Again, go to any enthusiast forum and ask around. There is a reason water cooling went from a tiny niche to the norm for the high end enthusiast market.

    I haven't attacked *you* at all, I don't know you and have nothing against you. I have an issue with FUD and with people who troll discussions about products they have something against. I don't like SFF PCs, they aren't for me. I do not spend my time trolling articles about products used to make them.

    Also, you continue to claim that there is an emotional reason to go water when hard data points say you are flat out wrong. Water is cooler, water is quieter. This is measured data, this isn't some feeling.
  • PeachNCream - Tuesday, June 23, 2020 - link

    I'm not debating that liquid cooling results in lower temps. Noise is a different critter as that varies based on what specific cooler you happen to be using so claiming something is universally quieter is incorrect.

    Back to the point of cooler. Sure a CPU will run at a lower temp, but if something is cool enough on some sort non-liquid HSF, then using a liquid setup will give you an on-paper advantage that won't matter. That's a point you're avoiding acknowledging as a result of personal bias.

    Your two primary points are moot. Your argument that liquid cooling is the norm is not supported by any statistical data from a credible source. What sample of sales data do you have at your disposal to support an assertion of popularity? Is it purely personal experience or do you have information you can supply that can support that?

    You didn't even read the entire post I made about leaks before quoting it as support for a perception of bias. If you had, you wouldn't have included it because you would have figured out I was advising against judging liquid cooling based on leak potential since we don't have good sample data available to cite it as an inherent problem. You're seeing what you want to see and making me into a threat to support an uninformed notion I have something against liquid cooling that warrants your spending so much effort to defend it. That's very emotional of you.
  • BenSkywalker - Tuesday, June 23, 2020 - link

    Do you not follow the high end CPU market? Legit question. Boost clock speeds vary based on voltage and temperature of the die, cooler running chips require less voltage so on both fronts there is a tangible and measurable edge to using water, in most cases it is mild, but in instances like the 10900k it can be a rather sizable margin.

    For noise water is quieter than air. American citizens are taller than Chinese citizens, that is both a true statement and obviously not universal.Yao Ming is taller than anyone I know IRL, but that doesn't make the overwhelming data less true.

    The leaks issue, we have a rather huge sample size between all of the various forums combined with most of the enthusiast tech outlets. Given that a water cooler leak is likely the second most catastrophic failure behind a PSU 'explosion' it is a rather safe bet it isn't common. I could say ants bring dynamite into a close and blow it up, can you link a study proving that's wrong?

    Air is "good enough"- and a ten year old dual core CPU is "good enough" for most things too. It isn't a emotional statement to say an Oct core is better.
  • MamiyaOtaru - Friday, June 19, 2020 - link

    far more cluttered? wtf? Yeah a tower cooler is larger than an AIO block, but you act like the radiator doesn't exist. It's bigger than most towers, and requires tubes running between the block and the radiator. You're still running fans through the radiator, plus pump noise. You sound like you spent some money on water and need to justify the expense Reply
  • MamiyaOtaru - Friday, June 19, 2020 - link

    tell me how cluttered this is http://chattypics.com/files/new2_vwdn60vl4h.jpg
  • BenSkywalker - Friday, June 19, 2020 - link

    That looks like an OEM system. If that's what you want, all the power to you. Reply
  • sonny73n - Friday, June 19, 2020 - link

    Mamiya, I wouldn’t waste my time replying to that... (how do you call a stupid person stupid without being crucified for it?).

    Anyway, his radiator fans don’t make noise but the fans on everyone’s air coolers do. And his water pump is completely silent. Oh, whoever uses air cooler don’t have that cool pump he has.
  • BenSkywalker - Friday, June 19, 2020 - link

    There is a measurement for noise that people have figured out, they use the term decibels. Using measuring devices they can tell how loud certain things are in relation to one another. All of the things we have discussed have been measured for the amount of noise they generate.

    Air cooler fans are the loudest out of the three(factoring for thermal dissipation).
    Water cooler fans are the middle tier(mainly due to being capable of operating at lower RPMs)
    Water pumps generate the least amount of noise out of these three devices.

    These are documented measurements, not feel feels of trolls that are trying to trash a type of technology in the comments of an article about said technology.

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