Ralph, Good points, thanks for the CPU and firmware clarifications--but from what you say, each "half" of that statement IS true. > < "The RAM limit for any computer is the amount the CPU can address> Maybe, "given sufficient DIMM slots" I suppose, but more to the point: > <"your system cannot use more than 1.5 GB no matter how much you > install."> Given your input, with the three DIMM slots his system has, and the firmware currently available, Alex simply cannot exceed the limit of 1.5 GB in his Digital Audio G4. I agree with you that there is almost no chance Apple would release a Firmware Update for any older Mac model just to allow more RAM access--what would be the benefit to them? They would really prefer Alex and others buy a new G5! I confess to being amazed that my new G5 can handle 8 GB--and slightly amused that we are back to having to buy RAM sticks in pairs again! Steve in Raleigh