I have both of these computers running right now with clean installs of xp pro. the first one is a 1.0Ghz p3 with 512 and the second is a 1.8Ghz P4 with 512. They both perform the same, except the onboard graphics on the p3 stink (tho it has apg slot) The p4 will boot from standby to music in 3 seconds flat while the p3 takes 20. Will the extra money spent on a bigger psu or 2 m2-atx (1 for motherboard and or for hard drive and usb hub, straped together) for the p4 be worth it? I'm leaning towards the p4 because i think it'll perform better with gps and video, but I'm wondering what you guys think. Thanks, Drew