Hey LB, when you installed that MaxPower, did you have to mess w/ the DIPswitch jumper setting? Also, is the ZIF chip a fixed or variable speed one? If its fixed, then yursick is correct, you cannot xlr8 it anymore, bus or cpu. I have a G3 MT upgraded w/ an XLR8 G3z 500. I could overclock the cpu to 533, but have not tried it. I once had an OWC zif that i overclocked, but i eventually killed it. In fact.. has alot of info on this....its in their tech pages i think. rock sdf