Actually I knew that already, but now I'm just pissed off. It was my case XION 450w with a 18A 12V rail. I installed my 7900GS, but after booting (with super low res), my computer won't stop rebooting after 4-6 seconds of logging in. My power supply is weak, but surely it can at least RUN the 7900GS at a less than optimal power, right? You guys really should help me before I either 1. Go insane-r 2. spend a lot of money on a PSU that might not even be the problem...

Btw, sometimes the computer makes a quick low pitched beep, yet I can't find what the beep code it...

Ayudanme!