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 - Wednesday, June 17, 2020 - link

    When will they leak? Had one going for about a decade now, hasn't happened yet. Also, saying they cool equally is just plain wrong. Reply
  • liquid_c - Wednesday, June 17, 2020 - link

    You have never used an AIO cooler. Of that, i’m sure. Reply
  • Beaver M. - Saturday, June 20, 2020 - link

    You have very bad hearing, of that I am sure. Reply
  • Lord of the Bored - Thursday, June 18, 2020 - link

    Repeat after me: I mostly want to feel superior to people that use technology diffrently than I do! Reply
  • Beaver M. - Saturday, June 20, 2020 - link

    Repeat after me: Projection doesnt help my case. Reply
  • Beaver M. - Saturday, June 20, 2020 - link

    Some do cool better. But not by much. Maybe 5 C at best. Thats not worth it at all, especially those that can do that are extremely expensive.
    But they are also louder. The pumps are hard to get silent even in very professionally damped cases, because its a very low frequency hum that vibrates the whole case. Imagine an external 3.5" HDD sitting on your desk.
  • ashoz85 - Sunday, June 21, 2020 - link

    Well thats short sighted, I moved from a desktop midi tower to an itx case (Old CM Elite 130) which sits the PSU above the cpu and the standard Ryzen 5 1600 cooler was too tall for it to fit.

    So i either chose a low profile air cooler (which basically couldn't breath which meant no overclock) or replace it with an AIO. The AIO was a much better fit for the job.
  • shaolin95 - Wednesday, June 17, 2020 - link

    When you have a system fully coordinate with RGB , it looks fantastic..so you are missing the point due to lack of knowledge or experience. Reply
  • PeachNCream - Thursday, June 18, 2020 - link

    Not sure that's an accurate assumption. People have a variety of tastes in what constitutes something that looks "fantastic" so you will see variance and differing opinions regarding what impact RGB has on a computer. If you enjoy it and feel it is worth the additional software and hardware along with all that comes along with it, then go for it and enjoy yourself. On the other hand, failing to note the possible security problems, additional raw materials investment (and potential environmental damage the extras require - every little bit we conserve of our world helps in some small way) and other ramifications would be irresponsible of us. Reply
  • ritawgoodman12 - Thursday, June 18, 2020 - link

    Make 6150 bucks every month… Start doing online computer-based work through our website. I have been working from home for 4 years now and I love it. I don’t have a boss standing over my shoulder and I make my own hours. The tips below are very informative and anyone currently working from home or planning to in the future could use this website. W­­W­W.iⅭ­a­s­h­68­.Ⅽ­O­Ⅿ Reply

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