I have a 1 ghz athlon and a 300 watt power supply. It is the bare min suggested by AMD and I did not have any problems when I first put it in. But sense I have added a few hard drives (3 HD's right now) and 4 case fans and a high end video card and I can see now that I need to put in a bigger power supply probably going to go with a 350 or if I find a good price a 400 watt. I am a gamer so I do need to have a bigger one but if you are not going to put that much hardware into the computer than a 300 should be no problem. Bradley Marden [log in to unmask] PCBUILD maintains hundreds of useful files for download visit our download web page at: http://freepctech.com/downloads.shtml