Multi Processor

1. Does Windows see Hyper Threading as computer with
multi processor?

2. Are there any waysthat u can detect if the computer
has multi processor?

Ken

pawar
Mon Jan 12 02:38:29 CST 2004

use WMI to enum processors...

"Ken" <cyyu@lyncsoftware.com> wrote in message
news:00f601c3d8d9$61d8b200$a001280a@phx.gbl...
> 1. Does Windows see Hyper Threading as computer with
> multi processor?
>
> 2. Are there any waysthat u can detect if the computer
> has multi processor?
>
> Ken

Maxim
Mon Jan 12 04:07:29 CST 2004

> 1. Does Windows see Hyper Threading as computer with
> multi processor?

Yes.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com

Pavel
Mon Jan 12 06:05:23 CST 2004


"Ken" <cyyu@lyncsoftware.com> wrote in message news:00f601c3d8d9$61d8b200$a001280a@phx.gbl...
> 2. Are there any waysthat u can detect if the computer
> has multi processor?


See KeQueryActiveProcessors() and KeGetCurrentProcessorNumber

-- PA

anonymous
Mon Jan 12 17:56:19 CST 2004

If I called KeGetCurrentProcessorNumber for a processor
support Hyper Threading, would it return 1 processor or 2?

Ken

>-----Original Message-----
>> 1. Does Windows see Hyper Threading as computer with
>> multi processor?
>
>Yes.
>
>--
>Maxim Shatskih, Windows DDK MVP
>StorageCraft Corporation
>maxim@storagecraft.com
>http://www.storagecraft.com
>
>
>.
>

Don
Mon Jan 12 20:30:48 CST 2004

It will return 0 or 1 to indicate that you have two processors.


--
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Remove StopSpam from the email to reply

<anonymous@discussions.microsoft.com> wrote in message
news:072d01c3d967$ac80ffe0$a301280a@phx.gbl...
> If I called KeGetCurrentProcessorNumber for a processor
> support Hyper Threading, would it return 1 processor or 2?
>
> Ken
>
> >-----Original Message-----
> >> 1. Does Windows see Hyper Threading as computer with
> >> multi processor?
> >
> >Yes.
> >
> >--
> >Maxim Shatskih, Windows DDK MVP
> >StorageCraft Corporation
> >maxim@storagecraft.com
> >http://www.storagecraft.com
> >
> >
> >.
> >

zmau
Tue Jan 13 03:35:27 CST 2004

"Maxim S. Shatskih" <maxim@storagecraft.com> wrote in message news:<uIbcKPP2DHA.3140@tk2msftngp13.phx.gbl>...
> > 1. Does Windows see Hyper Threading as computer with
> > multi processor?
>
> Yes.

In PC magazine, someone said that Hyper Threading can not be fully
used unless the OS does some adaptation. With respect to NT, it was
stated that these adaptation are expected later OS versions (I do not
remember exactly the words but that was the general idea).
On the other Hand Intel stated that this feature is Opaque to the OS
(i.e. the OS does not need to do any adaptations.
What is happening in reality ?

Thanks
Maurice

Don
Tue Jan 13 07:37:43 CST 2004

It is opaque for operation, but not performance from what I know. Since
scheduling on the second hyper-thread can take bandwidth from the first you
want to have the OS be smart of scheduling. This is why Microsoft wants for
a 2 physical processor machine the processors to be 0 = (processor 0
hyperthread 0), 1 = (processor 1 hyperthread 0), 2 = (processor 0
hyperthread 1), 3 = (processor 0 hyperthread 1)
and not alternating on hyperthreads


--
Don Burn (MVP, Windows DDK)
Windows 2k/XP/2k3 Filesystem and Driver Consulting
Remove StopSpam from the email to reply

"Maurice zmau" <zmau@netvision.net.il> wrote in message
news:a4a129d6.0401130135.54f32c71@posting.google.com...
> "Maxim S. Shatskih" <maxim@storagecraft.com> wrote in message
news:<uIbcKPP2DHA.3140@tk2msftngp13.phx.gbl>...
> > > 1. Does Windows see Hyper Threading as computer with
> > > multi processor?
> >
> > Yes.
>
> In PC magazine, someone said that Hyper Threading can not be fully
> used unless the OS does some adaptation. With respect to NT, it was
> stated that these adaptation are expected later OS versions (I do not
> remember exactly the words but that was the general idea).
> On the other Hand Intel stated that this feature is Opaque to the OS
> (i.e. the OS does not need to do any adaptations.
> What is happening in reality ?
>
> Thanks
> Maurice

Maxim
Tue Jan 13 18:12:51 CST 2004

> In PC magazine, someone said that Hyper Threading can not be fully
> used unless the OS does some adaptation.

"Unless the OS will be SMP" they mean.

> On the other Hand Intel stated that this feature is Opaque to the OS
> (i.e. the OS does not need to do any adaptations.

I trust Intel's officials more then technically illiterate media people.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim@storagecraft.com
http://www.storagecraft.com