[topgear]

@ Gauravs90 - it's not that 32bit OS can use only 4GB mem@ max. The OS makers only made consumer grade 32bit OS to support 4GB ram @ max. That's why XP and Vista x86 edition supports only 4GB mem @ max.

A 32 bit OS can also support 128GB mem @ max. Tha's why windows server 32 bit data center edition supports 128GB of mem and enterprise edition 64GB and their x64 consuterparts supports 2TB mem.

all 32bit windows 7, vista and Xp supports 4GB at max.
BTW, vista ultimate and xp x64 supports 128GB mem max but win 7 ultimatex64 supports 192Gb mem.

@ krishnandu.sarkar - I'm using xp x64 and vista x64 both. From my experience I can tell
you will nget some great HDD response time and data through output if you use x64 edition. But there is not any substantial difference in mem bandwidth and cpu performance.

If you use softs like maya, 3ds max, VMware ie rendering and virtualization app s a lot with 4GB meme minimum you can benifit from x64 OS.