I'm running with 512mb right now, and it's starting to tick me off. I'm a multi-tasker. I use a lot of programs at the same time and I have my Norton Protection center running at all times... I also play games now and again that use a lot of RAM and I can barely play with only 512mb. I am planning to upgrade to 2GB soon, that is if I don't get a new machine first. 1GB would be better, but I would still use it all up.