been there man your BIOS observation is a good clue. if artifacts appear only after Windows loads the driver, but not in BIOS or in Safe Mode (which uses the Microsoft Basic Display Adapter), that leans towards driver/sotfware ;) if they show up in BIOS too, think hardware.
oof if artifacts persist after DDU and an older driver, and even appear in BIOS, back up your data and look into warranty. dont keep stress testing a card that shows artifacts in BIOS.