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 only manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is being acquired 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 Noctua NH-U12A CPU Cooler Testing Results, Maximum Fan Speed (12 Volts)
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  • Qasar - Friday, July 12, 2019 - link

    for $100 bucks more then the NH-D15, i would hope so, or it would be a rip off ;-) Reply
  • FreckledTrout - Friday, July 12, 2019 - link

    Yeah this did remind me of my old Thermalright TRUE 120. I have it in a friends computer running an old 2600K I donated. That cooler is/was very nice. Reply
  • mjz_5 - Thursday, July 11, 2019 - link

    Would love to see how this compares to the stock Ryzen coolers Reply
  • keyserr - Thursday, July 11, 2019 - link

    Thanks for the review. I'm becoming one of 'those' people that likes silence in their PC. I was waiting for this fan to come out and build a system around it! However, I have since read that the NH-D15 / NH-D15S is quieter and this review suggests that since it performs well at low rpm. Lower rpm than than the NH-U12A. I might also wait for the fanless monster.. for a mITX beast system :) Reply
  • Hyper72 - Saturday, July 20, 2019 - link

    I'm with you there. I like my computer out of hearing and sight so it's great to see a nice review! Reply
  • jabber - Thursday, July 11, 2019 - link

    Just love that fake limb plastic colour. Reply
  • Ashinjuka - Thursday, July 11, 2019 - link

    While this is interesting and I understand why AnandTech would review it, similar to feelings expressed towards the extreme high end PSUs and folks asking for more realistic and everyday reviews to compare to, I'd love to see you folks do a round-up of some of the middle and lower end 3rd-party CPU coolers that are out there.

    My last few "utility" builds have used PCCOOLER Corona GI-X2B's and... they're fine. They're really fine. Basically silent under normal use. One 120mm fan with a LED ring, 2 heat pipes, rated for up to 105 TDP, for $15.

    Sure, I wouldn't try to do any major overclocking with that but I suspect that for the 99%, these cheaper, less halo-premium CPU coolers are perfectly adequate and still way better than, for instance, stock Intel.
    Reply
  • webdoctors - Friday, July 12, 2019 - link

    +1

    Really wish it was compared to regular budget coolers like the 212 in the graph.

    At $100 its hitting the AIO water cooler heatsinks.

    I see at newegg the CoolerMaster 212 is $35 with free shipping,

    Cooler Master Hyper 212 LED with PWM Fan, Four Direct Contact Heatpipes, Unique Fan Blade Design, Red LEDs, Optimized Bracket

    I'd love to know how this compares to that, its sort of the benchmark (pardon the pun) comparison point since its been used for ~10 yrs and on a multitude of platforms.

    Using the stock AMD Wraith cooler, and putting that $100 into a better CPU would be much better, you'd get a substantial upgrade in CPU performance.
    Reply
  • piroroadkill - Friday, July 12, 2019 - link

    But they did compare it to the 212 in the thermal resistance vs sound pressure level graph.

    The difference is stark.
    Reply
  • Qasar - Friday, July 12, 2019 - link

    " At $100 its hitting the AIO water cooler heatsinks." maybe.. but how well would those AIO's cool compared to this one ? here. AIOs start at $65 cdn, but i doubt they would cool as well as this would.. i bought an NH-D15 for my 5930k, and at full speed.. my case fans are louder, and it keeps the cpu pretty cool even overclocked.. i liked the NH-D15 so much.. i grabbed one each for all of my comps, Phenom 2, an AMD FX, and my 2 X58 based cpus. Reply

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