You're confused, a 32bit app can access more than 2GB if the flag is set large large address aware, this will only work in a 64bit OS. A 32bit OS is the one with the per app memory access limit. The game shouldn't crash if it runs out of VRAM because it goes to main ram, so all you will get is pausing because main ram is much slower. A 64bit OS for games is the way to go, don't even think about a 32bit OS.