EDIT: I'm not with the computer now but I've just realised that if it was a 900MHz then it must be a G3.. I was just helping a friend to sort out their G4 ibook as it was chugging along. It's only got 256 Mb of Ram at the moment and he will be upgrading the Ram. He was wondering why it was a bit slow editing a 12 gb video file! (with 1 gig of free disk space). It's a bit better now but I've a couple of questions. I noticed that it was running Panther and I was wondering if Tiger would see a performannce improvement on this machine or whether it would in fact slow it down. Aslo is it OK to run non paired ram in these machines. Like would it be fine to put in a one gig stick next to the current 256. And are these easy to put the ram in yourself? Thanx. DB.