If it is set to Automatic, the G5 ratchets the processor down like a laptop; i.e. when you are not doing anything strenuous, the processor does not perform at its highest level. It is supposed to kick into high gear when the system detects a heavy load, but does not seem to do so adequately. When playing the Battlefield 1942 demo on automatic mode, I could barely play it at 640 x 480 lowest graphics mode. Once I set the processor to Highest, I could then play smoothly at 800 x 600 with medium graphics. One caveat, it yet has to be seen how this will affect the life of your processor.
[robg adds: We discussed this before relative to new PowerBooks .... it seems at least some new desktops are also set to Automatic out of the box.]

