I know that there is a lot of upside to the latest hardware, especially GPU cards and the PS3, but these systems can only run specialized work units.
That's why I have kept my systems as mostly 5.04 console units, since these can fold any general work unit and a broader range of science than the specialized units.
Are you running on OS/X or OS/9?
OS X of course. Running the SMP client on the iMac.