It depends on how you use your pc. If you play COD4 for example, and then use itune's to listen to music in the background. You will actually notice a small difference, not in FPS but in system responsiveness, well ok and maybe in fps, but not enough to justify the price difference. In all truthfulness though the sweetspot for XP-32 bits is 2gigs. But vista-32 bits loves 4gb because of all the crap in the background. Unless you do what I did and disable the sidebar and all the other useless crap, but at that point your pc looks like XP sorta, which if you were going for Vista for pure cosmetic appearance then your a SOL.