Originally Posted by Lasereth

You will need between 350w and 600w depending on the brand and model. The brand DOES matter more than any other component in the entire system. I recommend PC Power and Cooling, Enermax, Thermaltake, Antec, SeaSonic USA, Corsair, Sparkle brands. You need to make sure it has two PCI-E connectors for videocards if you want to do SLI. 350-400w should be fine with those brands if you get 1 GPU. 2 GPUs I would do 500-600w.