Re: Corsair AX850 enough for 3930K and two GTX 580s in SLI?
Should be good for your current build yes. with the 680's/ 780's im not 100% sure the power consumption on those but it should be less than the 580s so you could easily go with that PSU or you could bump it up to a 1KW one to guarantee no issues for the next gen cards.
CPU - I7 2600K 4.5 GHZ
RAM - 8 GB DDR3 1600mhz
GPU - GTX 570 Classified