How about a 2nd HDD to have both 32 and 64 bit XP? Hard drives are pretty cheap, these days. Don't forget that some 32 bit games come with 16 bit installers. And there are other things that don't run on XP64. Some of the CD copy protection programs don't work, for which many have resorted to using copy protection cracks on their legitimate games.

As far as performance, in most cases with 32 bit apps are concerned, you won't notice much, if any, performance boost. That said, XP 64 seems to be more stable and a bit faster than the 32 bit version. I have also noticed that DOSBox has a lower CPU load in 64 bit Windows than 32 bit Windows on the same machine. I am not the only one that has noticed this. The main performance boost will come with certain kinds of 64 bit programs.

Zup wrote:

I've bought a new motherboard and VGA for my old computer. My system will be an AMD 64 3200+ with nForce4 chipset.

How much RAM?

Zup wrote:

- With Windows XP Pro 32 bits, I'll have 32 bit compatibility, but how much performance will I lose?

Depends on many things, but on standard rigs it's nothing to write home about.

I wonder how you can't afford to have two OS's on the same computer. WTF. Do you have like an 8GB hd or something? heh.

Where I live, WinXP Pro 64 costs the same as a 300GB harddisk. I'd take the latter 😁

I've got two hard disks, but they're pretty loaded. And I've got three OS's in the same computer (DOS 6.22+Win XP+SuSE)... so I didn't want to make room for a fourth OS.

My new computer has 1 Gb RAM (DDR400/Dual Channel), so I'm thinking about installing VMWare.

The biggest advantage of the 64 bit extensions is the direct addressable space >4 GB. With only 1-3 GB RAM, 32 bit addressing is just as efficient, you won't gain much by using the 64 bit extensions.

From what I've heard, 64-bit Windows isn't really worth using yet. It's like Win2K when I first tried it - lots of hardware doesn't have driver support yet and some that does has unstable drivers that cause issues.

Thanks everybody for the answers. I guess I'll try installing both Windows XP, but I'll have to make room in the hard disks...