AMD to Disclose Details About Bulldozer Micro-Architecture in August

[Hornet331]

There are very good examples of that, but that is because Windows XP Task Scheduler lacks intelligence. When Intel had the Pentium D Smithfield and a Pentium Extreme Edition of it that had Hyper Threading (Core and Frequency being the same), the Pentium D was faster in all applications with 2 Threads because Windows XP in the EE usually assingned them to the first two Cores, that were the Processor first Physical Core and its own Logical Core, leaving the entire second Core on Idle.
I don't think that you should need to program with Hyper Threading in mind, but this happens because you should make sure than your application is aware of Hyper Threading to not use Logical Cores before Physical Cores are fully used, however, that should be a workaround to compensate for the Task Scheduler stupidity of not knowing what Core is Physical and what one is Logical, and assign the Threads first to the Physical and then to the Logicals. If the Task Scheduler was more intelligent, you shouldn't actually need Hyper Threading specific considerations because the OS would take care of it.

I call BS on that since windows xp is aware of HT cores.
http://download.microsoft.com/downlo...ad_Windows.doc

Read this doc, it describes how the thread assigning in xp/2003 works. Since Windows XP the scheduler tries to always utilize physical idle cores, before logical cores. But if the software your using is hardcoded to use certain cores, without asking the os which cores are smt cores and which not, its not the fault of the os. Since it provides the possibility to do that.