History: The PowerMac G4 (PCI Graphics) was announced along with the PowerMac G4 (AGP Graphics). Originally, the PowerPC 7400 (G4) chip had been planned to debut in the G4 AGP model, but Apple was not able to get the new machine ready in time. The G4 PCI had been in the works in case of such an event, and allowed Apple to ship 7400-equipped machines while they worked out the final bugs of the G4 AGP. There were extreme supply issues with the G4 initially and this was further compounded by an "erratum" in the initial revision of the 7400 that effectively lowered the ceiling of the chip to 450MHz. As a result, all models of the G4 were "speed dumped" in October.