its not , 32bit cant utilise 4 gig its a limitation of the OS (cue the PAE posts
) , that said the extra 500mb a 64 bit install could use wont improve your performance one bit mate , however a 64 bit game on a 64 bit machine is differant altogether , for example Crysis in 64 bit mode runs a good 15 fps faster on my rig than the 32bit one and you may even find your operating system whizzes along alot smoother