We take a look at two high wattage power supplies from companies known for their solid product lines; the Silverstone DA750 model features a single 12v rail and is rated at 750W. The FSP Epsilon has four 12v rails and combined offers up to 900W. We stress test these units in a real world environment with the most power hungry vga cards out there, two ATI HD 2900 XT in Crossfire. Read on to find out