Microsoft is to offer a datacentre version of Windows to support hybrid computing using 32-bit/64-bit systems (x64).
High-end server manufacturers are adopting the AMD Opteron and Intel Xeon EMT64 hybrid 32-bit/64-bit processors for their next generation of datacentre products.
This has led Microsoft to develop a datacentre version of Windows Server x64.
The company initially said Windows Server 2003 x64 (Extended Edition) would be aimed at users who did not require a datacentre version of Windows.
Previously, Microsoft recommended that users requiring datacentre alternatives for high-end Unix and mainframes should use Itanium-based products.
Last week, John Barozan, a member of the Windows development team, said, "Our partners are building datacentre-class machines with eight processors or more with x64 [hybrid chips], so we have to have a datacentre operating system.
"Windows on Itanium is for very large database and line-of-business applications," said Barozan. "You will see us commit all our server software to Windows Server x64."
Among the server software being redeveloped for x64 processors is Microsoft’s flagship e-mail server, Exchange. The company has yet to commit to an Itanium version of Exchange.
By 2007 Microsoft expects an entire software stack to be available for x64 servers. Native support for x64 is being developed for databases and SQL Server, Oracle and DB/2 would be available. SAP is also adding support for Windows x64.
For Microsoft the biggest benefit of the x64 architecture is that it overcomes the 4Gbyte memory limit of 32-bit servers, which prevents the application from accessing more than 2Gbytes of virtual memory, no matter how much physical memory is installed in the server. With x64, an application can use up to 1Tbyte of memory, according to Microsoft.
Brad Waters, development manager at Microsoft, said users would see a major improvement using Windows Terminal Services on Windows Server 2003 x64 edition on an x64 server.
Waters said the upper limit for Terminal Services on a 32-bit server was about 280 users, because the operating system would run out of memory.
However, an x64 server would be able to support 500 users, Waters said.