Question Intermittent freezes & crashes after upgrading CPU ?

Sep 13, 2022
I'm completely new here, so please forgive if this is the wrong forum.

My pc has been running reliably for the last couple of years (since build). Ten days ago, I upgraded the processor from a Ryzen 5 to a Ryzen 9 5950X. Since then I have had some unexplained crashes, where the computer simply freezes. No response to anything on screen (image just freezes); no cursor; CNT-ALT-DEL doesn't work; hard-reset doesn't work (I have to turn the power off at the PSU). The computer will then restart as if nothing went wrong (no error messages about improper shutdown) and there are no entries in Event Viewer. There is no commonality in what the computer is doing when this happens - it can happen when left idle, or when working (I mainly use my machine for 3d rendering, so it works hard).

These crashes are occurring every three or four days. I thought it might be a temperature thing and replaced my cooler, but temp is only just hitting 60C at 100% load for extended times. Idle temp is 35C.

Does this point to a dodgy CPU or is there something else I should explore? All suggestions welcome. Please let me know if more info is required.

CPU - Ryzen 9 5950X
Mobo - Asus ROG STRIX X570F (latest BIOS update)
GPU - Nvidia GeForce RTX 2060
memory - Corsair Vengeance RGB Pro 64GB (4x16GB) DDR4
PC4-24000C15 3000MHz

Many thanks in advance.