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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  • alyarb - Friday, June 28, 2024 - link

    I'm so old I still have a Lian-Li PC60 Reply
  • James5mith - Friday, June 28, 2024 - link

    I customized the hell out of my PC60 back in the day. Even had one of the purple anodized variants at one point. Reply
  • PeachNCream - Friday, June 28, 2024 - link

    "...with more than just a touch of modern flair..."

    I know writing is hard, but that one was like the local hair stylist trying to sell me a bottle of conditioner or some half-baked home improvement television series starving for words to fill the silence so the audience doesn't find something else to visually assault themselves with.
    Reply
  • thestryker - Friday, June 28, 2024 - link

    Do we know if this pump is an Asetek or their in house design?

    An AIO with a screen isn't really up my alley, but I know with the Galahad II the one with a screen was Asetek and the others were the in house design.
    Reply
  • Eliadbu - Sunday, June 30, 2024 - link

    I don't know if it's in house design, but Asetek gen 8 pumps have distinct coldplate
    which squared and has different shape and screw holes than their own stuff, by the look of this AIO it looks more like their normal and performance trinity and not like Asetek design.
    Reply
  • GeoffreyA - Saturday, June 29, 2024 - link

    I'm curious what happened to the site yesterday, all the comments being locked. Reply
  • Ryan Smith - Saturday, June 29, 2024 - link

    We were doing maintenance, which goes a lot faster with the DB locked. Reply
  • GeoffreyA - Saturday, June 29, 2024 - link

    All right. Thanks. Reply
  • Mikad - Sunday, June 30, 2024 - link

    Are the first paragraphs of these recent articles AI generated? Asking because they are cringeworthy. Reply
  • Ryan Smith - Tuesday, July 2, 2024 - link

    No. Company policy doesn't allow us to use AI writing tools. Also, AIs make for terrible tech writers.

    (That said, some days it's hard to write a good intro, especially when you've already written so many. Can't win 'em all, but we try!)
    Reply

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