I have a 5900x (zen3), and apparently I got a bit unlucky with the silicon and ended up with a CPU that’s slightly unstable at its stock voltages and stock boost clock. The system would freeze and reboot randomly, and the bios would report an MCE error. This crash could be reproduced with near 100% success by doing sha1 hashing specifically for some odd reason. This is not a Linux issue, it’s a hardware defect.
It may be an Asus motherboard specific thing, but I found a workaround by going to the bios settings, precision boost overdrive, and increasing the voltage scalar to like 7. Now it’s been two years and I have only ever had it happen once since I changed that, so I’m happy.
Some of it probably comes from other companies that are unable or unwilling to relicense it even if Nvidia wanted to