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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  • Daeros - Tuesday, May 17, 2022 - link

    You should be careful with your explanation of SPL: while +3db is double the energy, it’s a relatively small change from a human perspective. While it is subjective, a human-hearing-based doubling in perceived loudness is around +10db(a). In your example of +30db, it’s more like 8-10 times as loud *to a human listener*.

    There’s a pretty good breakdown of all this over at http://www.sengpielaudio.com/calculator-levelchang...
    Reply
  • abufrejoval - Tuesday, May 17, 2022 - link

    A pulse!

    I have a pulse!

    Well it's only a fan and not one of the stories Ian was supposed to have left in the pipeine, but well, seems the fan isn't all bad.

    Could someone please send AT some mainboards, CPUs, GPUs and SSDs to review?

    Please?
    Reply
  • DanNeely - Thursday, May 19, 2022 - link

    The power and cooling editor is writing articles about cooling devices. Shocking there.

    I don't know if any more Ian articles are stuck in the pipeline somewhere; at this point I doubt it though.

    The mobo editor, Gavin's been ill (covid) recently.

    With Ian's departure though, I think Ryan's the last full time person on staff with everyone else moonlighting after their day jobs.

    The corporate overlords appear uninterested in anything other than siphoning as much money out as they can; the number of authors has been going down for years with people who leave generally not being replaced and the site slowly dying as a result.
    Reply
  • usiname - Tuesday, May 17, 2022 - link

    Wont be bad to add low end box collers from AMD and Intel. After all this type of coolers target exactly the owners of the box coolers Reply
  • Sttm - Tuesday, May 17, 2022 - link

    The Noctua U12S is $50. How much are you really saving going for one of these? $20? $10? For a machine you are going to use for at least a year right?

    Invest the $20!
    Reply
  • firewrath9 - Tuesday, May 17, 2022 - link

    Thats a slippery slope, why not pay another $25 on top of that for a U12A?, and U12S is 70 euro on amazon de and $70 on amazon US, also it looks butt ugly and you gotta pay $10 more for the chromax. Noctua is a good company, but their coolers are generally overpriced and dated. Reply
  • at_clucks - Tuesday, May 17, 2022 - link

    If the performance (cooling, noise, reliability) is right up there what does "dated" even mean? You buy coolers for their novelty value? Draw the price/performance plot and pick the best cooler in the segment you care about. Reply
  • blackmetaversa - Tuesday, June 14, 2022 - link

    What is Metaverse?
    The Metaverse is well known around the world, with numerous definitions addressing assorted sentiments. https://www.blackmetaverse.io/ To rapidly characterize the significance of Metaverse, we should consider a three-layered web fueled by computer generated reality (VR) and expanded reality (AR). The Metaverse is tenacious, self-maintaining, endless, interoperable, and continuously, and these highlights are its key attributes.
    Reply
  • Sttm - Tuesday, May 17, 2022 - link

    The gray one is $50 on Amazon. Reply
  • necroperversor - Thursday, May 19, 2022 - link

    SPC released Fortis 5 dual (tier more, than Fera 5 daul) for like 205zł = 47$ = 44 €, I will post graph with comparison of NH-U12S, Fera 5, Fortis 5 and few more. Fera and Fortis are better than U12S, with price 26€ less, but it is price in Poland, I don't now why on amazon.pl/amazon.de the Fortis 5 dual cost 73€, yes it's still quiter. https://youtu.be/f7IBV8LEeOc?t=203 (3:48 for noise test) Reply

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