I upgraded my system to a Ryzen 9850X3D, an RTX 5080, and a Lian Li 1000W power supply. Since then, the computer has started crashing intermittently. It can run for several days without problems, and the crash usually happens only once before the system works normally again for a while. I've already tested the RAM with MemTest, ran a GPU memory test for about 20 minutes, updated the BIOS and chipset drivers, and performed a clean installation of the graphics drivers. I'm running out of ideas and would appreciate suggestions for tracking down the cause.
3 Answers
Try resetting the RAM to its default SPD settings, with any EXPO or manual memory tuning disabled. Some AMD systems can be unstable with certain memory timings even when a short memory test passes. If the crashes stop at stock settings, you can gradually test different memory speeds, timings, or voltages to find a stable configuration.
Check Event Viewer and look at the system logs immediately after a crash. Also check whether Windows created any minidump files. Tools such as BlueScreenView can help identify a driver or kernel component involved. The generic message about an unexpected restart only confirms that the shutdown was unclean, so the dump file is usually more useful.
The best time to inspect the logs is right after a crash, before the relevant entries get buried. Filter Event Viewer for critical and error events, and check for driver-related warnings around the exact crash time. If there’s a minidump, that should provide a much clearer lead than the generic unexpected-shutdown event.

I checked Event Viewer, but it only reports that the system restarted without shutting down cleanly. I’m looking through the minidumps now and trying to figure out whether the kernel is involved.