Long story short, I have a 20 pin power supply and no adapter, so I run it like that. It runs an ATI X300 video card perfectly, but when I put in the XFX 7800 GTX, it wont get past the motherboard screen before crashing, and thats even if I get video to start with. Near as anyone can tell its because of the power supply, so I am waiting on a newer one later this week.