Hi, Dick. I have the same machine loaded up with 2GB (4 512M DIMMs), working beautifully in OS X. Don't know about 1GB sticks, though - I believe the current machines (and OS) are limited to 2GB ceiling. Rick >I have 1024 installed (4 x 256K DIMM) and wonder if there is any reason to >consider replacing some of the 256's with 512's or even 1 GB's that are >being offered on the local market. > >This old 1999 version G4 would probably barf on a 1 GB memory stick. > >Dick