As I understand it, OS X should not perform page outs or use swap file unless there is not enough available memory. However recently I've found that I've been seeing said page outs. What strikes me as odd is that I have 4GB of RAM, and yet I run a web browser, an instant messenger, a 3D game or so like World of Warcraft and Second Life, and iTunes. For these common uses I'd have thought that 4GB should be more than enough. I'm not noticing any performance problems; it just struck me as odd, I suppose what I want to ask is, is it normal? PS: Just in case the attachment is not showing, it's usually just a few MB on the swap file and the same on the page outs, usually after around six hours of use.