On 23 Dec, 2004, at 10:56, Casey Coulon wrote: I have a Power Mac G4 AGP 450 and want to add some more memory as the current 384 mb is just not enough anymore. I know Apple suggests using PC-100 Synchronous DRAM (SDRAM), 3.3 volt, 64-bit wide, 168-pin module, Unbuffered. Question is this, can I use PC-133 instead of PC-100? If so, would it matter if the current installed memory (3 x 128 mb) is PC-100? Has anyone else tried this? Any problems? I used differently rated RAM for about a year without any problems that I could determine. I had two 100s and two 133s in a Gigabit Ethernet G4, total 512Mb, until I splurged for four 256Mb 133s. Except for having more active RAM in the G4, I really haven't seen that much difference between the old set-up and the new.