In my 2008 uni MBP, i currently have 2GB of RAM. Decent, but if i have iTunes, Word, and several Chrome windows up, it starts to beachball and really slow down. I'm not even sure if I'm using up all the RAM, it just starts to get laggy. My friend's MBP has the same 2.4Ghz C2D processor but with 4GB of RAM. Man, he can have a ton of apps open and not run into issues. I've re-formatted many different times and still have the same thing. I have a 2GB stick on the way, which would give me 3GB of RAM. There was a test a while back that found 3GB didn't offer much different to 4GB (LINK) of RAM. But i believe the tests were done on Tiger & Leopard, which only used 3.3GB. My question is, is there that much of a difference with 3GB (1 X 2GB, 1 X 1GB) and 4GB (2 X 2GB)? Obviously the 4GB will be snappier, but by how much?