I am running a late 2005 G5 2.0ghz. Started off with the stock 512mb and I now have 6 gigs. How do I know when I reach the point of diminishing returns? I know some programs like video editors will just love ram always. My curiosity is about doing normal activities. How do I differentiate if my computer is being slow because of lack of ram while I do my daily multitasking or being slow because its just slow over all.