you mostly just have to worry about the amps on these newer power supplies. if it has 4 rails at 18 amps each, then each plug going into a video card will supply that card with 18amps. so if you have two pci-e connectors going into a card you will have 18x2 amps for that card. a tpq-850 can run 2xGTX280s with plenty of peripherals as long as you balance them out along the rails.

even if it blows out just send it back to antec for a brand new one :)

they have killer warranties on their products.

Hey man sorry to bother you with such a noob question, but does the Antec tpq-850 combine the 850 watts amongst the 4 12volt rails? What I mean I guess is, can one of the 12volt rails supply like 350 watts ect. to one of the 12volt rails running at 18amps without blowing?