You want general info? Here it is. Clockspeed is determined by the chip's multiplier and its FSB (multiplier x FSB = clockspeed). Therefore you can overclock your chip by either increasing its FSB or multiplier (or both). It is not possible to adjust the multiplier on P4 chips. It can be done on AMD chips, but only after you physically modify the chip. I rather doubt it can be done at all on iMacs. This leaves with the FSB. If your BIOS allows for FSB adjustments, then you've got it made. Otherwise, you'll have to hope that the motherboard has some sort of jumper-FSB adjustment. Otherwise, your only hope wouldbe some sort motherboard mod which would probably be beyond the technical abilities of even most enthusiasts. Good luck with your OC, and if it works, let us know what you did and how it increased your performance.