spontaneous reboot, machine check events, AMD ryzen [closed]

Solution 1:

It seems this is a CPU hardware problem. In the AMD community forums (https://community.amd.com/thread/215773) it was suggested to either disable SMT or OpCache as a workaround until this gets fixed.

I disabled OpCache in the BIOS and the mce: [Hardware Error] messages during boot-up disappeared. I have two identical systems, which had the same issue with the freezes/reboots. Until now both systems didn't freeze.