> There a lot more benefits then additional address space for applications
> when using a 64bit OS with a 64 bit CPU. One of the biggest that is
> independendt of the appliations is the ability of the OS to load/move/store
> data using 64 bit registers instead of 32 bit so data can be moved in 1/2
> the number of instruction exectutions. Another benefit is many of the 64bit
> instructions used by the OS can perform the same amount of work as 2 32 bit
> instructions back to back so again cutting down execution time.
> I do agree that many vendors have not yet supplied 64 bit drivers for their
> hardware to MS approval on the WHQL list for use in 64bit Vista so waiting
> till you know that you have full 64bit driver support is a good idea.
You're certainly correct about the other benefits of the 64-bit OS, but,
speaking from personal experience, x64 Windows XP does not seem to
provide any speed increase discernible by the user compared to x86
version. In fact, it's been shown ( http://tinyurl.com/3agqz7
running apps coded for 32-bit in x64 Windows XP actually makes them run
a little more slowly, and some games won't run at all. You need the app
to be recompiled for 64 bits (and often more RAM) before x64 Windows
allows these apps to run faster that they do on x86 Windows XP. I'm not
aware of any such testing of 32-bit apps in 64-bit Vista, but I don't
see why the results would be different.
When x64 XP was released, cNet had this to say about it, "The bottom
line: Only software developers and high-end workstation users will see
real benefits from Windows XP Professional x64 Edition; everyone else
should stick with 32-bit Windows XP instead."
So, I'll repeat the opinion that unless one spends a lot of time using
an application that's been recoded for 64-bits, it's probably wiser, for
now, to stay with the 32-bit operating system.