How do I enable XMP or DOCP in BIOS to get my RAM to run at its advertised speed?

Boot into BIOS, find the memory settings, and enable XMP (Intel) or DOCP (AMD)—it’s literally one toggle. The exact menu name varies by motherboard brand, but look under “OC,” “Ai Tweaker,” or “Advanced Memory Settings.” On modern AMD boards, you’ll also see EXPO. Just pick the profile matching your kit’s advertised speed (e.g., 3200 MHz). No need to tweak voltages or timings unless it won’t boot; if it crashes, clear CMOS or update BIOS.