I have a 20" iMac G5, 1.8 with 1Gb of ram. Performance is absolutely fine for almost everything but I find that things get a little laggy when using it for CAD work (Vectorworks). I guess it is the high resolution on he 20" screen that works the graphics card hardest but I was wondering if upgrading the ram would help? I usually have Mail, Safari, Notebook2 and Filemaker and maybe iTunes running as well but none of these applications seems to suffer from lag. Buying a couple of sticks of 1Gb ram would be far cheaper than splashing out on a new Mac (although any excuse ) and anyway I love my iMac and don't want to part with it just yet. Has anyone noticed a performance boost from additional ram on a set up similar to mine?