I am looking to get another amd 6870 so I can crossfire, and was just wondering if I needed a higher wattage psu. Current system: PSU: Corsair HX750 Motherboard: Gigabyte x58A-UD3R CPU: Intel Core i7 930 CPU Cooler: Coolermaster V8 GFX Card: Reference amd 6870. Memory: 6GB (3x2GB) 1600MHz DDR3 Corsair Dominator 8,8,8,24 HDD's: 3 - 1 SSD, 2xSATA2 HDDs Optical Drive's: 2 - 1 BD writer, 1 BD read PCIe Wireless card (PCIe x1 or x4 i don't know) I have tried using the extreme psu calculator, that spits out 600 which seems too low, I tried ASUS's and that spit out 1050 which is far too high, the guru review says 700, which seems closer to the figure. Anyone running 2 6870s? what psu do you use? anyone know if my 750 is enough?