WinXP32bit vs WinXP64bit: What's the difference in performance?

Your worst performance hit will probably be in the hardware drivers... it's not that hardware companies can't write GOOD 64 bit drivers... it's just that since 99+% of installed XP is 32 bit, they don't have much reason to write 64 bit drivers at all, let alone optimized 64 bit drivers... 64 bit XP has a 32 bit sub-system, allowing it to run almost any 32 bit app, except those that deal directly with the kernel... Antivirus, hardware drivers, some encryption stuff, VPN, that sort of software. Those MUST be 64 bit to work at all.

64 bit should have a slight edge over 32 bit in performance, unfortunately since the programmers haven't spent the time on it, in reality it doesn't usually end up being true in real-life... 64 bit's main advantage is the ability to access more ram than you can afford to buy :)

for your question "what's the real difference between 32 and 64?"

that number if bit refers to a computer architecture, where address length is 64 bits. The number of addressable location is 2^64, which is more than 1 Terabyte

64 bits CPU also means that its register length are 64 bits wide

In terms of performance, it don't meant better performance. Remember that performance is about the speed of execution, not the precision of the result. 64bits offers higher percision, if taken advantage of

64bits windows just means that it support the 64bit architecture

One important thing is that since you have 4GB, 64bit Windows is your only option

Its not true that you only need 64 bit if more than 4GB memory

Because that addresable location inclues your graphic card memory, and the operating system reserve a certain amount of addresable location for its own use

So, if you run 32bit windows, your memory will be less than 4GB.

You don't really have a choice, but to use 64bit windows

xp64 will run 32 bit apps without any problem, there is no compatibility issue. The real challenge is to get the hardware drivers for 64bit edition. 32bit drivers wouln't work. Every thing else is good unless you run any 16bit or DOS apps ( not supported). Your games should run fine if the graphics hardware is installed with 64bit drivers.

Check

http://en.wikipedia.org/wiki/Windows_XP_Profession...

Best of luck,

:)