Processors

[greenp]

A little backstory: Purchased a new system I assembled myself - 3950x, Noctua D15, Asus TUF Gaming X570 Plus Gaming.

Everything was at stock settings and for two weeks it was fine until I ran the CPU benchmark of Sisoft Sandra (the latest version). The system hanged and after a couple of reboots couldn't post. It was stuck at initializing the VGA (the diagnostic LED). I though it was the video card and tried another one with the same result. Sent everything back and they discovered it was the CPU and exchanged it for another 3950x.

Now the system is running fine but a friend helped me underclock and undervolt it a bit as I prefer a stable system as these stock voltages of 1.4 seem rather high.

We set the CPU to 3300mHz (CPU core ration to 33x), the VDDCR CPU Voltage Override from Auto to 1.05 and disabled the Precision Boost Override and the Core Performance Boost. Ran Prime95 and the system appears stable. The snapshot is while the system is running Prime95. https://imgur.com/a/p741Q8U

Would I gain a bit more performance if I use voltage offset of say 0.2 and turn PBO and CPB back on while leaving the core ration to 33x?

I am willing to sacrifice performance but I prefer to have a processor which will not fail.

I am welcoming opinions on these settings. Are they safe? Is static voltage fine?

[qbtheslayer]

Oddly enough, using PBO with an offset undervolt can actually improve performance.

Here is PBO enabled:

And here is PBO with a -0.14375V offset:

Is this just margin of error?  Maybe, but when I then cranked every fan in my system to 100% (yes it was extremely loud) with an iCUE H100i RGB PRO XT this is what I get:

So these CPU's love to be cool and finding a stable undervolt is not only good for power and thermals...  it's also good for performance.

QB