Windows XP Pro SP2 64-Bit (x64) Updateable

Windows XP Pro SP2 64-Bit (x64) Updateable

The primary benefit of moving to 64-bit is the increase in the maximum allocatable system memory (RAM). Windows XP 32-bit is limited to a total of 4 GB, which is, by default, equally divided between Windows kernel and application usage. Using the /3GB switch in the boot.ini file forces Windows to limit the kernel to the upper 1GB and provides up to 3GB for applications. Windows XP x64 can support much more memory; although the theoretical memory limit a 64-bit computer can address is about 16 exbibytes (16 billion Gibabytes), Windows XP x64 is currently limited to 128 GB of physical memory and 16 TiB of virtual memory. Microsoft claims this limit will be increased as hardware capabilities improve.

Since the x86-64 architecture includes hardware-level support for 32-bit instructions, WoW64 simply switches the process between 32- and 64-bit modes. As a result, x86-64 architecture microprocessors suffer no performance loss when executing 32-bit Windows applications. On the Itanium architecture, WoW64 was required to translate 32-bit x86 instructions into their 64-bit Itanium equivalents—which in some cases were implemented in quite different ways—so that the processor could execute them. All 32-bit processes are shown with *32 in the task manager, while 64-bit processes have no extra text present. 

VCFQD-V9FX9-46WVH-K3CD4-4J3JM