I currently am using a 5 year old G5 at my office. I am a social science research coordinator so I use this machine for a multitude of tasks, including running SPSS, filemaker, and MS office on a daily basis. This machine runs extremely slow, especially when multiple programs are open. This is very impeding to my productivity as I often have to wait several minutes while it "thinks" when I am switching between programs. I am getting really tired of seeing the colored spinning beachball. I know the memory is a biggest problem. I'm currently running on 256 mb. there is plenty of drive space available on the 80gb hard drive. The processor is 1.8GHz. My question is, is it worth it to upgrade the memory in this machine to its max, 4gb or should we just replace it? Can I be certain that upgrading the memory will improve this machine's performance substantially?