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

Introduction & the Cooler Testing Results
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  • Flunk - Thursday, October 14, 2021 - link

    It would have been nice to see a high-end air cooler in the results, such as a Be Quiet Dark Rock Pro 4, to compare the difference between high-end air and AIOs. Many people cross-shop air coolers and AIOs and without at least one comparison point it's hard to know how they stack up.
  • satai - Thursday, October 14, 2021 - link

    I would be quite interested how this compares with higher Noctua models too.
  • vanish1 - Thursday, October 14, 2021 - link

    Their bench page has air cooler results. You should try looking first instead of crying that the info isnt being spoon fed into your mouth, baby.
  • Slash3 - Thursday, October 14, 2021 - link

    You should probably read the review first before commenting.
  • vanish1 - Thursday, October 14, 2021 - link

    You're an idiot. Anandtech has it's own bench page with a backlog of testing results that anyone can access at the top of the site where it says "BENCH"

    You can go back to the peanut gallery now.
  • Slash3 - Thursday, October 14, 2021 - link

    Reading comprehension is important. Keep at it though, you'll get there eventually.

    Flunk wrote "It would have been nice to see a high-end air cooler in the results."

    If you can't tell the difference between the aggregation database and results in a directly referenced review, I don't know if there's much hope left for this conversation.

    I feel it's important to also point out that the referenced Be Quiet Pure Loop 280, the Dark Rock Pro 4 or the common Noctua NH-D15 are all entirely absent from the Bench database. Oops. You'd know this though, because you checked it. Right?


    Consider breathing exercises, or yoga. You seem to need some help with focusing your attention.
  • vanish1 - Thursday, October 14, 2021 - link

    NH-D15 is just an updated NH-D14 and congratulations you picked one cooler that wasnt there, make sure to hold on to that one cooler tight so you get to say you are not wrong like a bit.ch

    There is a bench full of air coolers, if you're stupid enough that you need every piece of information spoon fed to you and you cant figure out anything on your own, stick to tomshardware
  • sor - Thursday, October 14, 2021 - link

    It’s not as much what you say as how you say it. It’s possible to politely point out that the info might be available, it doesn’t require someone to make an ass of themselves.

    It’s also totally valid to suggest that extremely relevant information be collected into an article. It would make the article itself better.
  • Oxford Guy - Friday, October 15, 2021 - link

    'you picked one cooler that wasnt there'

    Only the industry standard in high-end air cooling. Nothing important there!
  • milleron - Wednesday, November 17, 2021 - link

    Dear Mr. Vanish, you have a serious problem. I think you can be helped with drugs and psychotherapy, but it'll require knowledgable and dedicated psychiatrists and psychopharmacologists. Meanwhile, I'd stay out of bars if I were you; with your present approach to life, you probably would not get out of one with all your teeth.

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