Recently Microsoft announce 64-bit version of Windows XP. The hardware platforms supported are AMD 64 and Intel EM64T as processor family this mean:
The Intel and AMD architectures are binary compatible and there is only one version of XP that supports both.
As OS Windows XP 64-bit edition is almost the same as XP but it supports 128GB RAM and 16TB of virtual memory. The limit on XP is 4GB physical and virtual RAM (32 bit address space 2^32= 4294967296 bytes ~ 4GB).
XP 64 supports 32-bit app's running them in WOW64 (Windows on Windows 64). This is an x86 emulator that runs on 64 bit. It separates 32 -bit app's from 64-bit ones and this means that they cannot use shared DLL's 32-bit DLL works only with 32-bit applications and the same for 64-bit. The speed of emulation is almost the same as in Win XP, but some multithread app's could have problems.
This means that for obtain full advantage of your high end processor applications must be ported on native 64-bit mode then speed can increase up to 40%. Another problem is that all device drivers in your system must be 64-bit.
Another problem is that 16-bit app's are not supported (no more MS-DOS compatibility mode) and some 32-bit app's have 16-bit installers - they will not work too.
If you need the new features Go! Move to 64-bit edition if no it is better to wait and receive more drivers and app's in their 64-bit versions
11.05.2005