I just upgraded my main box from an Athlon 2600+ to a P4 630 last night. Got a new ASRock 775Dual mobo (PCI-X and AGP on the same mobo is awesome, btw) and the system runs like a dream. No hiccups at all on 1080i Quicktime 7 video (my Athlon could barely handle 480i QT7 without slowing to a grinding halt). Everything is way faster now. I've been able to switch to 1280x960 for gaming resolution (up from 1152x864) and could probably pump it higer. I haven't tried out any 64-bit stuff yet, so I can't comment on it. My only concern is that it's running a bit hot (~50C Idle and I got it up to 68C under Prime testing overnight) but it seems to be ok, and it hasn't throttled itself at all yet. Also, LGA775 slots suck. I'm having trouble thinking of a worse way they could have picked for heatsink installation.