This is something that’s been asked since the introduction of consumer-level processors bearing the “x64” nomenclature.
It feels like just yesterday that Intel and AMD fanboys were at odds over the Athlon 64.
Analogous to the shift from 16 to 32-bit computing, the jump to 64-bit has been a slow one.
Windows XP x64 never took off, though64-bit versions of Vista did, thankfully.
At this point in time, nearly everyone is on the same page about the transition.
This permits you to use about 2.75-3.5GB of RAM after IO reservations are factored in.
Windows 7bumps that up to 192GBwith the Professional version and above.
