Windows XP 64-Bit Edition will run on the Intel® ItaniumTM processor as the platform for workstation users who are reaching the memory limits of 32-bit systems. The key difference between 32-bit and 64-bit Windows XP-based computing lies in the 64-bit version’s ability to use much more system memory. Windows XP 64-Bit Edition will initially support up to 16 gigabytes of RAM and up to eight terabytes of virtual memory. Physical memory support will grow in the future as hardware capabilities expand. Data in memory is accessed thousands of times faster than it is on a disk drive, offering a tremendous performance benefit for applications that are developed to use this greater system memory. In addition, Windows XP 64-Bit Edition has been designed to take advantage of the superior floating point capabilities of the Itanium processor.

The 64-bit Microsoft Windows platform will provide high availability, advanced scalability, and large memory support based on the Intel® Itanium™ processor family with its extensive multiprocessing features, powerful floating-point arithmetic extensions (up to 6.4 Gigaflops at 800 MHz when tuned for 3-D graphics performance), and multimedia-specific instructions.

Windows XP 64-Bit Edition provides a scalable, high-performance platform for a new generation of applications based on the Win64TM API. Compared to 32-bit systems, its architecture provides more efficient processing of extremely large amounts of data, supporting up to eight terabytes of virtual memory. With 64-bit Windows, applications can pre-load substantially more data into virtual memory to enable rapid access by the IA-64 processor.

Windows XP 64-Bit Edition supports up to 16 GB of RAM and 16 terabytes of virtual memory, enabling applications to run faster when working with large data sets. Applications can preload substantially more data into virtual memory, allowing rapid access by the Intel Itanium processor. This reduces the time for loading data into virtual memory or seeking, reading, and writing to data storage devices, thus making applications run faster and more efficiently.

Windows XP 64-Bit Edition has been optimized specifically for the Intel Itanium processor, and benefits from its key features, such as the Explicitly Parallel Instruction Computing (EPIC) design. The EPIC instruction set, which differs from the IA-32 (x86) instruction set, enables Intel Itanium processors to perform up to 20 operations simultaneously.

Windows XP 64-Bit Edition also takes advantage of the increased floating-point performance, or the raw number of calculations that can be processed in a given period of time, of the Intel Itanium platform. An 800-Mhz processor running at peak performance is capable of up to 6.4 GFLOPS—essential power for data-crunching scenarios such as Mechanical Computer Aided Engineering (MCAE) and financial operations.

Windows XP 64-Bit Edition is the first step in 64-bit workstation computing from Microsoft. As data sets and memory requirements continue to grow, there will be an increasing demand for the capabilities of 64-bit Windows on Intel Itanium.

The Microsoft Windows XP 32-bit and 64-bit operating systems will be developed in tandem, providing customers with a full range of computing environments from which to choose.