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How is the Noctua NH-U14S TR4-SP3 working for you?
Did you add a second fan to it?
Temps at full Keyshot load?
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The Noctua cooler is working out great.
I did start out with a second NF-A15 140mm fan mounted on it, but at full load, it caused an annoying whine due to turbulence in the cooler. Removing the second fan increased the CPU temperature on full load 1 to 2 degrees, at most. I think the second fan is not really worth it, at least in my setup.
I do have a Noctua NF-S12A PWM fan mounted "axially" to the CPU cooler on the back of the case to blow hot air from the cooler out of the case. I have 3 of the same fans on the bottom of the case to take fresh air in, and 3 additional fans on the top to blow air out. So this machine has 8 fans (1 on CPU, 7 in case) in total to keep things running smooth.

Maximum temperature at full KeyShot load, running the camera benchmark for 10 minutes, is 78°C (monitored with AMD Ryzen Master Utility) today in Aarhus, Denmark (not the hottest climate

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Note that I haven't done and don't plan on overclocking this CPU.
All in all, Noctua NH-U14S TR4-SP3 is a great cooler for Threadripper 3970X. Very decent cooling performance, quite silent even on load and hassle-free (knowing that no pump will ever break down).
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