my m8 in work has a pre-built machine with onboard VGA. He wanted to play games so i recommended an 8800GT. Bought the 8800GT (which needs 22-24 amps) and an apporpriate PSU (Corsair VX450W) which delivers 33 amps on the 12v rail which is more than sufficient. installed the PSU, fired up teh system = works install the 8800GT = nothing, machine comes on, all fans power up, but thats it, just sits there and wont post. tried the 8800GT in my rig and it works lovely. the motherboard is an Asus P5VD2-VM i think its a motherboard fault with the PCI-E lane. anyone got any idea's? all thats in this PC is 2x SATA HDD's and an IDE DVD ROM. Theres a front panel for some USB ports and thats it. Corsair website tester showed the 450W as being suitable.