One of my front Noctua black 140mm industrial high performance PWM fans stops spinning under low load, connected to my ASUS APEX MB Smart fan control. And never spin full speed due the high air flow at half speed CPU variable boost cap 5.3. HT off. 10900 all 10 cores.

4 hours ago, Noel said:

What do you have the 7800X3D voltage at now?  Any other changes need to happen besides lowering cpu voltage?  I have a Noctua NH-U12A and under MSFS load average CPU core is around 64C with a brief peak of 70C once.  Obviously these are totally fine but if it can be lowered w/o loss of perf all good.

After getting memory setup correctly I haven't done anything beyond BIOS defaults for CPU performance.  I disabled HT or SMT whatever it's called.  Anything else you can recommend to improve performance w/o introducing instability?  I had all cores on my 9900K at 5gHz for the first 3y, then reduced it to 4.9gHz and increased voltage a bit as I was getting some instability and lockup crashes.

 

I use PBO -30, you can try that first and run a 10 min Cinebench and see if it is stable, if not try -20 and so on, you can also try -40 if it is stable at -30, some chips can run that low as well, but it's unusual, mine crash at -40.