Alright I'm planning to upgrade to a GeForce 8800GTS 320MB, my CPU right now is a AMD Althon 64 3500+. I just want to know will a 450Watt Power Supply be enough to run my computer???1. You must list your total AMPS on the 12 volt RAIL of your power supply, thats what really counts when upgrading ure video card, Not the watts.

2. Your power supply is gonig to NEED a PCI-E 6 pin connector to connect to the 8800GTS 320mb, and make sure u have enough room. That video card takes up 2 filler bracketsI have no idea where to find that information.I currently have a power supply that has 450Watts, and thats all I know about it.http://educations.newegg.com/tool/psucalc/index.html450W PSU will be enough to power your computer with a 8800GTS.It depends on how many watts your card needs (most video cards are over 100W) and then use the rest of your hardware (anything that takes power) to add up the total. Use your rail as was mentioned earlier, to help you make sure it's right. Your system will be unstable and PSU could get fried if you exceed the power draw.Check Here...