I have Bryce 5 and its running on a 966 PIII with 512 megs and haven't had any problems at all, except sometimes on lauch.. I get an .exe error... reboot and runs fine, but that only seems to happen when I launch Bryce work for awhile close it...reopen it, close it and then reopen it again... 3 times with no reboot seems to fubar it.