Multi-core CPU systems, need a help

I have a single threaded application working under 3 different multi-core
systems, one with XP 32 bit, one with Vista and one with Windows 2003.
On XP the workload is all on a single core, while in Vista and 2003 the
workload affects both the two cores.
Am I correct in suspecting the 2 latter OS'es (Vista and 2003) are
internally splitting the single thread between more cores?
And if so, is there a way to tell Vista (or 2003) not to use this feature so
to let the single threaded application work on one core only?
--
News Microsoft

You can do this manually by setting the affinity in Task Manager. I don't
know of a way to set it automatically.

--
Kerry Brown
Microsoft MVP - Shell/User
http://www.vistahelp.ca


"Villi Bernaroli" <a@b.invalid> wrote in message
news:e6kk2aWEIHA.4772@TK2MSFTNGP02.phx.gbl...
>I have a single threaded application working under 3 different multi-core
>systems, one with XP 32 bit, one with Vista and one with Windows 2003.
> On XP the workload is all on a single core, while in Vista and 2003 the
> workload affects both the two cores.
> Am I correct in suspecting the 2 latter OS'es (Vista and 2003) are
> internally splitting the single thread between more cores?
> And if so, is there a way to tell Vista (or 2003) not to use this feature
> so to let the single threaded application work on one core only?
> --
> News Microsoft
>