64-Bit Choices to Increase

Intel has announced that some of its future 64-bit processors will implement the x86-64 instruction set, which extends the x86 address and data paths to 64 bits, but still runs 32-bit applications natively. Intel will continue to support the IA-64 architecture used by its Itanium processors, and Microsoft will supply versions of Windows and other software products for both architectures. Although Microsoft’s 64-bit products are coming to market very slowly, Intel’s support for the x86-64 architecture and new security features in these processors should accelerate the use of 64-bit computers for both servers and desktops.

The Key Processor Differences

The key difference between the two 64-bit architectures lies in how they support existing 32-bit applications.

Because Intel’s IA-64 is a new architecture with a new instruction set, it is not natively compatible with the 32-bit applications in use today. Instead, Itanium includes an on-chip translator that converts 32-bit x86 instructions to native IA-64 instructions, a process that results in slower 32-bit performance. Because of this architecture, Intel has promoted 64-bit computing primarily for servers and high-end workstations running new 64-bit applications.