Windows Vista forum: 64 bit Vista: Advantages and Disadvantages

Heh, even if you found some information on this topic, it is interesting nevertheless.

The difference between x86 and x64 computer architecture is that one reads in 32bit and the other reads in 64bit. The salesman was right, x86 (32-bit) cannot read anything between 3-4GB. x64 (64-bit) will allow you to exceed that.

The advantage is that 64-bit programs tend to run faster (from experience) and tend to run smoother at the same time.

The disadvantage is that once in a while you will need to find 64-bit versions of a program.

A 64-bit OS will have no effect on a 32-bit program's execution speed. If you have a 32-bit and 64-bit version of the same app, odds are the 64-bit version will be a bit faster, but only to any significant degree if it makes use of a lot of 64-bit variables.

To the average user, aside from being able to use more than 4GB of RAM, and needing to make sure to use only 64-bit drivers, there is not going to be any real difference between the 32 and 64-bit Vista.

Running 32-bit apps on a 64-bit OS requires both hardware AND software support.

You need a CPU capable of executing 32-bit code AND you need 32-bit libraries for the programs to link against. When you install a 64-bit Windows, it uses something called WoW (Windows on Windows) to make for compatibility with 32-bit apps. Basically it installs a "shadow" set of 32-bit DLLs needed to run 32-bit apps. So 32-bit apps are still subject to all the same limitations they would be on a 32-bit OS.

And just for the sake of completeness, x86-64 is just the name of the instruction set AMD came up with for the Athlon64. It largely preserves the backwards compatibility with the x86 instruction set we've had since the 8086. Kind of a double edged sword, since there's a very very large amount of x86 software out there, but at the same time it is really hamstringing developments in computer power consumption reduction and other areas. Anyway, Intel calls it EMT64 in their line of CPUs. It's almost exactly the same thing, it's just Intel trying to save face after their IA64 instruction set sank like a stone with the very expensive blunder that was the Itanium that gave AMD the time it needed to take the lead in the 64-bit instruction set game.

Unlike most people think, due to the x86 backwards compatibility, it's not a fully 64-bit instruction set. The memory limit is 48-bits not 64. Still, it will be probably at least another 5-10 years before we start bumping into that limit. With any luck we'll be on 128 or even 256-bit CPUs by then.

Yea, in regards to 256-bit.. I remember once I tried to customize a Mac Pro and it was at 256-bit processor. I was amazed. It might be sooner than we think.

I got an HP 64 bit Vista last year. Several old software and drivers will not install and/or run:

1. Corel Draw 7.0 circa 1998: installs, does not open. $150 to the garbage.
2. Zone Alarm Security Suite, current version: will not install. ZA told me they will not write a 64 bit version. $100 to the garbage.
3. Olympus 8x10 dyesub photoprinter circa 1999 : error message when installing driver, Olympus told me they will not write new driver. $800 to the garbage.
4. Canon DR2080 scanner circa 2000: error message when installing driver, Canon told me they will not write new driver. $800 to the garbage.

Total cost of "upgrading" to 64bit: $1,850 (a lot more than the price of the computer).