I didn't really test it flat out. I ran distributed.net on it for about a week solid, and it didn't complain, and I ran a DVD player in software decode mode with no skips and only marginal stuttering (I hadn't installed the video drivers that allowed hardware decoding). All that was pretty solid. Interestingly, distributed.net was faster in XP than in 98 (6.02 vs 5.86 Mkeys/sec)

The friend of mine who owns it is going to do video processing and encoding on it, and that'll take a while to set up. If there's anything significant I'll let you know.

Have fun,

Paul