Thanks neo1980. Yet more related INTEL news, lets change sundays to "chip news days" -Ed ;)
WHITE PAPER on Microsoft's site now gives its full stance on Intel's hyperthreading technology, which will be implemented on the desktop with the launch of the Pentium 4 3.06GHz processor.
The report, last updated 24th September, is aimed at BIOS developers, system manufacturers (original equipment manufacturers), and independent software vendors (ISVs).
The 116K Microsoft Word document mainly deals with server microprocessors, but provides guidance to software developers. It warns that no Windows OS will support "logical" processors unless the hyperthreading is started by the BIOS and identified by MADT.
The article also describes the Windows licences suitable for hyperthreading, and its implications on Windows 2000 and .NET Server, which are not "HT aware".
While .NET Server and W2K will run on HT enabled systems, they won't identify hyperthreaded processors and Microsoft won't let them do so in the future.
There's a chart showing the processor limits for Windows 2000, and a warning that if the logical processors don't run in the BIOS start sequence, there could well be "critical problems" in performance.
Windows XP supports hyperthreading thread scheduling, "aggressive HALT" of processors in the idle loop, and using the "YIELD" instructions to avoid "spinlock contention".
News source: The Inquirer