While the world’s most powerful supercomputers run Intel Itanium 2 multiprocessing units, Microsoft Corp. does not want to support Intel’s Itanium-series chips in its operating system designed for clusters, instead, the company qualifies its forthcoming product for x86-64 chips, namely AMD Opteron and Intel Xeon.

A report over CNET News.com claims the Redmond, Washington-based software maker said its Windows Server 2003 Compute Cluster Edition for clusters that contain up to 128 processors will not run on Intel Itanium 2 chips without disclosing the exact reasons for the move, but noting that it had something to with “demand for the product”. It is unclear, whether future incarnations of Windows for clusters will support Intel Itanium 2 chips.

Cluster is an array of servers that work in collaboration, but are physically independent. Intel positions Itanium processors for high-end servers and supercomputers – huge machines that consists from numerous building blocks that may be considered as independent, but that still form a single complex. The main difference between high-end servers and clusters is that the former employs top technologies, while clusters can be formed from numerous low-end machines. Typically clusters use Linux operating systems, supercomputers and high-end servers employ various OSes, including Microsoft Windows Server 2003.

Microsoft’s move will also likely prompt many analysts to speculate as to whether Microsoft will eventually pull its support for Itanium 2 in general in the future, CNET News.com notes. The company has pulled it support for different server chips in the past, due to slack demand. Years ago, Microsoft produced, or committed to produce, a version of Windows for Digital Equipment’s Alpha processor; the MIPS processor, originally developed by Silicon Graphics; and IBM’s Power chips. All of these projects were ultimately scotched.

Since Intel Itanium 2 chips require software to be especially written for the IA64 architecture, software makers like Microsoft will hamper availability of appropriate software, market share gaining for the Itanium 2 chips may slowdown.

Microsoft is expected to release beta version of Windows Server 2003 Compute Cluster Edition in the first half of 2005, the final version is said to be ready in the second half of the year.