Microsoft hops on the 64-bit bus

Microsoft on Tuesday said it had released a beta version of its Windows XP operating system for 64-bit PCs based on Advanced Micro Devices' new Athlon 64 processor.

Dubbed Windows XP 64-Bit Edition for 64-Bit Extended Systems, the operating system will run on PCs with the Athlon 64 chip and also workstations using AMD's Opteron chip, Microsoft said.

Gates looks ahead to 64-bit era Bill Gates, chairman, Microsoft

The announcement is a key vote of support for AMD, which is attempting to line up a number of software partners to support its new 64-bit chips--the kinds of partners it will need to support the chip in the company's attempt to reach the upper echelons of the PC market. The 64-bit measurement refers to the amount of memory that a chip can access via the PC's data bus at any one moment.

One of the most notable aspects of the new operating system will be Windows on Windows 64, a feature that allows people who have current 32-bit applications to continue running those applications after upgrading to the 64-bit version of Windows XP. The feature is made possible by the construction of the AMD's 64-bit chips, which support both 32-bit and 64-bit applications.

"We?ve heard from our customers that, until now, the inability to efficiently run 32-bit applications on 64-bit systems has been a major barrier to investing in 64-bit technologies," Chris Jones, vice president of Microsoft's Windows Client Division, said in a statement.

However, Microsoft confirmed Tuesday that the final version of 64-bit Windows won't be available until the first quarter of next year. The test version, which Microsoft released this week, was supposed to have come out mid-year, with many analysts expecting a final version by the end of this year.

The reason is that the company wanted to synchronize its release with a service pack for Windows Server 2003, which is also due out early next year, said Microsoft product manager Brian Marr. Although the 64-bit version is designed to run on desktop machines, it is actually built on the Windows Server 2003 kernel, he said.

In an interview, Marr said Microsoft has not yet determined how much customers who buy 64-bit AMD systems now will have to pay for the new software.

One of the chief benefits of moving from 32 bits to 64 bits is the ability to add more memory to a PC. Customers using the new chip and software will be able to use more than 4GB of memory--the current limit of 32-bit computers.

While most performance PCs sold today come with between 512MB and 1GB of RAM, systems with between 4GB and 8GB will become more commonplace as 64-bit software works its way onto the desktop and as RAM module sizes gain more data storage capacity, AMD has said.

Although Marr acknowledged that the immediate appeal of 64-bit desktop computers is mainly to gamers and those who create videos, he said that in a year or two such systems could allow office workers to have their computers translate international phone calls.

Intel has not committed to a plan to bring 64-bit computing to the desktop. The company could create a desktop version of its Itanium processor, which runs 32-bit programs only through emulation, or it could follow AMD's approach, which adds 64-bit instructions to the existing Pentium-compatible architecture.

Marr said AMD's tactic makes sense.

"That particular architecture has the makings for something that can be widely adopted and used by a wide variety of customers," he said.

The chipmaker is also working with game developers such as Epic and software makers that author video-editing software, the company has said.