Question System reboots under load

Dec 22, 2022
Hi all,

In case you haven't read the title, I've recently been getting random reboots under load. It seems to happen more quickly in CPU heavy software, but it will just happen when the PC is under any kind of load.

The first thing I thought of was overheating, but it doesn't even go above 80°C before rebooting. I thought maybe it was a problem with the CPU but I've tried using a different CPU and the same problem occurs. There's no overclock or anything on the CPU.

I've done memtest86 and it has passed so I don't think it's a memory issue.

I've stress tested the GPU and had no crashes.

My only other thoughts is that it's either an issue with the power supply or the motherboard, but I don't have any of those spare and I don't won't to buy a new one just to find out it's not the problem.

I have reinstalled all of my drivers and updated my bios, which didn't fix the problem.

I have noticed that when it crashes I get an error in event viewer that says "A fatal hardware error has occurred" with event id 18. I've tried researching this but all I can seem to find is that it probably means a faulty CPU, but it's highly unlikely that both CPUs that I've tried would be faulty.

Does anyone have any ideas what the problem could be or any suggestions on what I can do to fix it?

AMD Ryzen 7 5800X
Corsair Vengeance DDR4 2x8GB RAM
MSI MAG X570S Tomahawk Max Motherboard
Corsair RM850e Gold 850W PSU
be quiet! Pure Loop 240mm AIO
Samsung 970 EVO 250GB M.2 SSD
Seagate Barracuda 4TB HDD