Before I changed from a 750w to 850w power supply. I tested my CPU in a friends x470 board, and it works flawlessly. I took everything out, reset the bios. Reinstalled all components. Disabled cpb and pbo, and didn't have a random reboot till the following morning. Still have kernel power error 41. It does it at idle and sometimes under load. I re-enabled cpb this evening. So we will see.
Got tired of all this BIOS tinkering and waiting for BIOS updates, so decided to RMA the 5800X 4-6 weeks ago.
New 5800X came in 2 days ago. Until now, my pc have not restarted at all. Even runs stable using XMP with 3600Mhz RAM.