Yes, 133 will work just fine Ron. The slower memory, in a mix will set the pace but the faster 133 memory will be a hedge to the future. There are many other issues besides RAM speed on overall performance; I can't tell the difference between 100 and 133 like I can between 256mb and 512mb. It is easy to tell when you don't have enough memory. roger Ron Steinke wrote: > On > 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?