Rbby258

Hi, thanks for helping. I added that and also tried and tested many other things but finally have answers! A faulty 13900k and some faulty cablemod customs psu cables.. I ordered a i5 13500 and another "cheap" z790 board to test hardware. Cpu didn't work properly on both boards. And cables would cause issues like loss of display if the pc was knocked.
 
Changing cpu and going back to my oem cables got everything working again. Have to say, cablemod have issued new cables at no cost and intel has agreed to refund my 13900k because "we can only offer you a refund for the CPU, because we were informed that the part or any alternate parts are currently out of stock and there is no ETA for new incoming stock" mad.

Is there a way I can disable the kernel disabling the core temporally? I've been using OCCT in bare metal windows and got the system stable but I still cant get them cores back? It was working originally.
 
Using "cd /sys/devices/system/cpu" followed by "ls" shows all 32 cores
 
Edit: I've figured it out. I added "mce=off"  under Syslinux configuration. The cores are isolated and used only on a vm so for the meantime I'm going to run like this and see how it goes.