PC Randomly Crashes During Games—Could High-Speed RAM or BIOS Be the Cause?

My computer crashes unpredictably, usually while playing Rainbow Six Siege. It may crash several times in one day, then work normally for a week or two. On one occasion, it crashed again before the system had completely finished booting. The event logs only report that the shutdown was unexpected.

I recently cleaned the PC and replaced the thermal paste, so I'm not sure overheating is the problem. My graphics and chipset drivers are up to date, but I'm unsure how to test whether the power supply is failing. I believe it is either a 750W or 850W model, though I don't know the exact unit.

My hardware is an AMD Radeon RX 7800 XT, Ryzen 9 7900X, 32GB of Corsair Vengeance DDR5-7200 memory, a 2TB Samsung SSD, and an MSI X670E Carbon WiFi motherboard. Could the memory speed, BIOS version, power supply, or another component be causing these crashes?