Hi! i used XP 64bits from more or less 2009 to 2019, when i change my Pentium 4 to a Xeon 775 and decide to install XP 32bits because this motherboard have floppy connector and 64bit Omniflop did not work well or at all (dont remember) in 64bit XP

For a period of time i had both windows, and i did not see a big performance difference, the only one is that i installed 8GB ram, and while in 64bit i can use all, in XP SP3, i use 4GB for system, and create a 4GB ram disk for swap, but still this did not affect performance in a level i can detect in every day use

I ran XP-64 on my Core 2 system for years with 8 gigs of RAM. It was stable as a rock and I had no issues with any software or games I ran. If you have a copy of it I'd say use it and don't look back.

Just wanted to add - don't get hung up on the RAM, 32 bit XP can use >4GB as well, through using PAE. Used to be officially supported at first, until SP2 (iirc) disabled it, but you can still reenable it with a patch.

Your pretty close to the mark. XP x64 is actually a "dumbed down" version of Server 2003.

Installing x64 for a gaming PC isn't going to hurt but not really offer any benefits.

The thing is most things of the era were written with XP x32 in mind especially games won't really take advantage of extra ram, multiple cores, etc, etc.
Business software would be noticeable, Even something basic like Outlook benefits from extra ram with large mailboxes.

Anything earlier then XP don't understand multicore cpu's and will treat each core as a separate physical CPU actually hurting performance. However any multicore CPU is crazy fast for Win2k your not really going to notice.

Provided the hardware supports it, I haven't personally experienced any particular issues with it performance or otherwise that are its own fault. However, it is worth noting that given most people ignored that it existed a lot of 64-bit software isn't compatible with it even if the 32-bit version supports XP. Either because they artificially block it by checking for SP3 to be installed which wasn't a thing on x64 being that it's Server 2003 based (might be a work around for this, haven't looked), or because it's compiled to assume Vista+ APIs are available. So if nothing else you're signing up for a bit of extra pain for a probably dubious at best benefit given that pretty much all software you will run is 32-bit anyway.

I think I'll try it out and see if it works best for me. I do a lot more than gaming on my PC, specs in my bio.

I think you'll like it. I used it personally for years and it was stable and I had no compatibility issues with any games or other software I used.

I believe any 64-bit PC deserves a 64-bit operating system.
I've installed Windows XP x64 on four PCs to date. I could find just as many drivers as for the 32-bit version. The only real issue with this release is that Windows Movie Maker crashes a lot; luckily, there's always the option of running it in a VM.
I've also installed the 32-bit version on two of those PCs. It ran at about the same speed, but on my Dell Precision laptop, Explorer would frequently freeze for five seconds at a time. I wouldn't consider this a big deal.
There are a few caveats when it comes to newer, unsupported hardware. Windows XP x64 requires ACPI; on motherboards where Setup can't detect it, one must use a modified BIOS or replace acpi.sys with a newer version. UniATA requires 32-bit Windows; a 64-bit version is planned.