card needs Power Consumption
up to 300Wadditional 6+8 pin PCIe power required
PLEASE remember this is in ADDITION to what the rest of the gear in your system needs as well. To provide an accurate answer I would need to know everything you have in your rig. checklist: hard drives, memory, case, cpu, cpu fan, chasis fan, cd/dvd rom, periphials, etc. and the model numbers plus how many of each.