This is strange.....I have a G4 AGP Power Mac with the original 450 mgz Processor. I had read that if you upgrade the firmare to 4.2.8f1 (the last version available) that you could install a 566 mhz processor. So......I installed an 566 mhz processor board, part # 820-1175-A. The system boots fine and all that, but "About This Mac" sees the chip as a 400 mgz Processor!!! What is going on here?......is the system only running on 400 mhz?? Any ideas? thanks for the help!