[tha k man]

though I doubt that many in this forum will want to hear this, the performance of Pro Tools Le 7.x on a good XP machine will usually be better than on a Mac.
I've had feedback from many XP users, who are saying that they have experienced significant CPU efficiency improvements in version 7 upwards. There are numerous reports/threads on this forum, stating the opposite for the Mac community.

Believe me, this is not something that I wanted to say - I've been a fanatical Mac advocate for the past 12 years, but even I have found that my dual G5 performs better under 6.9.2, than under 7. I have to different boot disks, so I can run the same sessions to compare CPU usage, and the simple fact is, that 6.9 is more efficient than 7, full stop.