Casey, I have the same machine and have been using a mix of PC-100 and PC-133 for over a year. I have 2 256K PC-100 and 2 256K PC-133 all from different suppliers and they seem to work perfect. I used to have some 128's and had no problem with them either Season Greetings Dick On 12/23/04 6:15 PM, "g4-request at listserver.themacintoshguy.com" <g4-request at listserver.themacintoshguy.com> wrote: > Date: Thu, 23 Dec 2004 11:56:30 -0700 > From: Casey Coulon <2AzBoys at cox.net> > Subject: [G4] Adding Memory? > To: G4 Forum <g4 at listserver.themacintoshguy.com> > Message-ID: <5BA6FF64-5514-11D9-99A0-00306576458A at cox.net> > Content-Type: text/plain; charset="iso-8859-1" > > 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? > > Thanks for your help and Happy Holidays. > > Casey