By Michael Cherry [bio]
Posted: Dec. 19, 2005

The following is an illustration accompanying an article published by Directions on Microsoft, an independent research firm focused exclusively on Microsoft strategy & technology. Each month we make one or more key articles available to non-subscribers.

Microsoft is starting on an aggressive path toward releasing 64-bit editions of key Windows Server System Software. Support for 64-bit processors benefits memory-intensive applications, such as online analytical processing (OLAP) systems, and compute-intensive workstation applications, such as computer-aided design. Because the x64 architecture is more popular with customers, only Windows Server and SQL Server will support the Itanium processors. All other 64-bit support will be for the x64 processors—AMD64 Athlon and Opteron 64-bit processor families and Intel's Extended Memory 64 (EM64T) family of processors.

Windows Vista client will be available in 32- and x64-bit editions for the foreseeable future. Itanium support will not be provided.

Windows Server will be available in 32-bit editions through Longhorn Server R2, expected sometime in 2009. Itanium support will be available as long as Itanium is viable in the marketplace.

Windows Compute Cluster edition, which never shipped as a 32-bit edition, will only be available as an x64 release.

In the Longhorn Server time frame (2007), Windows Small Business Server and a future mid-market server bundle code-named Centro will be available only as x64 editions. This may be due to the availability of Exchange 12, a component of these systems, as x64 only.