Echoing Mark, your computer will go as fast as the slowest Ram chip up to the 100,s it was built for. After that I believe it is your bus speed that defines the max speed and yours is 100. Definately get rid of any PC100 ram that is not 222 being the cycle count of its operation speeds. If any ram has a 3 in its cycle speeds it will slow all ram to that speed. Ask for a guarantee before you purchase and make sure you can return it for proper ram if they ship the wrong ones. It must all be PC 100 - 222 SDRAM for maximum performance. System Profiler will show all this info. jj No. it's not. it can't make use of them. even if they're all 133's. mark On Saturday, Jan 04, 2003, at 08:09AM, diane <diane at mathermotorsports.com> wrote: >Thanks, but that's not even close to the question I had asked. <G> > >I was wondering if it was worth spending the little extra on 133 >DIMMS when my G4 really only needs 100s