Looking at my acivity monitor I have shut everything down and except for safari and the activity monitor. I can see that all the items listed in the monitor add up to about 260Mb of real memory. There is 100Mb Wired, I suppose that has to do with the net. There's 266Mb Active I suppose that is all the things i can see in the monitor. There's 790Mb Inactive Don't have the slightest clue what that is all about but it goes a long way to explaining why I only have about 420Mb free. What is that huge chunk of Inactive memory and what does it mean for example if I want to open a bunch of large Photoshop files. Does that Inactive memory rob Photoshop of Ram it could use? Can anyone point me towards an article that explains exactly how OSX and G4's use ram. It used to be so clear with OS9. So at the moment even though I've not got anything open I'm using over a gig of ram. Say I wanted to do some heavy duty work with Photoshop would I be better off restarting first or would that have no effect.