Well in my research the 7790HD have a TDP of 85W. I have a current 6770HD on my system that have a TDP of 108W. I have a generic 650W 50% efficient though I will be changing it after a month or 2 with a "thermaltake 500W TR2 S 80PLUS TRUE RATED POWER SUPPLY"
So if I can run the 6770HD with a...