Do I need to enable XMP or DOCP for my RAM to run at its advertised speed?

Yes, you have to turn it on manually. RAM defaults to a safe JEDEC speed (usually 2133 or 2400 MHz) until you enable XMP (Intel) or DOCP/EOCP (AMD) in BIOS. Mash Del or F2 during boot, find the setting under “Ai Tweaker,” “OC,” or “Memory,” pick Profile 1, save, and exit. It takes two minutes and unlocks 10–20% performance you paid for.