Hyperthreading on dual-Xeon system

I have a dual-Xeon system (TYAN 2668ANR mobo) running XP
Pro with Hyperthreading enabled in the BIOS. Under Device
Manager, it shows ACPI Multiprocessor PC, but only 2 Xeon
processors are listed under the Processor tab. How come I
don't see 4 processors? A friend has a dual-Xeon Dell
workstation running XP Pro. His shows 4 processors under
Device Manager. Is my workstation not configured
correctly?

-Alan

I'm running an HP x4000 workstation, with four Xeon 2GHz CPU's, and with
Hyperthreading enabled, WinXP Pro is indicating four CPU's.

Make sure you have Hyperthreading enabled in your system's BIOS. If it
wasn't, you and enable it now, you may need to reinstall Windows.

Bill Crocker


"Alan" <alan@yellowknife.com> wrote in message
news:2d2001c395c9$a55d0dd0$7d02280a@phx.gbl...
> I have a dual-Xeon system (TYAN 2668ANR mobo) running XP
> Pro with Hyperthreading enabled in the BIOS. Under Device
> Manager, it shows ACPI Multiprocessor PC, but only 2 Xeon
> processors are listed under the Processor tab. How come I
> don't see 4 processors? A friend has a dual-Xeon Dell
> workstation running XP Pro. His shows 4 processors under
> Device Manager. Is my workstation not configured
> correctly?
>
> -Alan

Hi Bill,

XP Pro only supports 2 physical cpus+2 virtual cpus.
If you turn off hyperthreading you will only see that only 2 of your 4
physical cpus are in use.
To make use of all four physical processors you need Server 2003--with
hyperthreading you will have 8 processors in Server 2003.

--
Larry Samuels MS-MVP (Windows-Shell/User)
Associate Expert
Unofficial FAQ for Windows Server 2003 at
http://home.earthlink.net/~larrysamuels/WS2003FAQ.htm
Expert Zone - www.microsoft.com/windowsxp/expertzone
"Bill Crocker" <wcrocker007@comcast.net> wrote in message
news:GOWdnZbKcJDHUwyiRVn-sg@comcast.com...
> I'm running an HP x4000 workstation, with four Xeon 2GHz CPU's, and with
> Hyperthreading enabled, WinXP Pro is indicating four CPU's.
>
> Make sure you have Hyperthreading enabled in your system's BIOS. If it
> wasn't, you and enable it now, you may need to reinstall Windows.
>
> Bill Crocker
>
>
> "Alan" <alan@yellowknife.com> wrote in message
> news:2d2001c395c9$a55d0dd0$7d02280a@phx.gbl...
> > I have a dual-Xeon system (TYAN 2668ANR mobo) running XP
> > Pro with Hyperthreading enabled in the BIOS. Under Device
> > Manager, it shows ACPI Multiprocessor PC, but only 2 Xeon
> > processors are listed under the Processor tab. How come I
> > don't see 4 processors? A friend has a dual-Xeon Dell
> > workstation running XP Pro. His shows 4 processors under
> > Device Manager. Is my workstation not configured
> > correctly?
> >
> > -Alan
>
>

Oops!!! I meant to say, it has two physical CPU's, and with Hyperthreading
enabled, it appears like four CPU's.

Bill Crocker


"Larry Samuels MS-MVP XP (Shell/User)" <larry@mvps.org> wrote in message
news:%23d2OGielDHA.2772@TK2MSFTNGP12.phx.gbl...
> Hi Bill,
>
> XP Pro only supports 2 physical cpus+2 virtual cpus.
> If you turn off hyperthreading you will only see that only 2 of your 4
> physical cpus are in use.
> To make use of all four physical processors you need Server 2003--with
> hyperthreading you will have 8 processors in Server 2003.
>
> --
> Larry Samuels MS-MVP (Windows-Shell/User)
> Associate Expert
> Unofficial FAQ for Windows Server 2003 at
> http://home.earthlink.net/~larrysamuels/WS2003FAQ.htm
> Expert Zone - www.microsoft.com/windowsxp/expertzone
> "Bill Crocker" <wcrocker007@comcast.net> wrote in message
> news:GOWdnZbKcJDHUwyiRVn-sg@comcast.com...
> > I'm running an HP x4000 workstation, with four Xeon 2GHz CPU's, and with
> > Hyperthreading enabled, WinXP Pro is indicating four CPU's.
> >
> > Make sure you have Hyperthreading enabled in your system's BIOS. If it
> > wasn't, you and enable it now, you may need to reinstall Windows.
> >
> > Bill Crocker
> >
> >
> > "Alan" <alan@yellowknife.com> wrote in message
> > news:2d2001c395c9$a55d0dd0$7d02280a@phx.gbl...
> > > I have a dual-Xeon system (TYAN 2668ANR mobo) running XP
> > > Pro with Hyperthreading enabled in the BIOS. Under Device
> > > Manager, it shows ACPI Multiprocessor PC, but only 2 Xeon
> > > processors are listed under the Processor tab. How come I
> > > don't see 4 processors? A friend has a dual-Xeon Dell
> > > workstation running XP Pro. His shows 4 processors under
> > > Device Manager. Is my workstation not configured
> > > correctly?
> > >
> > > -Alan
> >
> >
>
>

That's cool--just didn't want you to be wasting all that horsepower if you
had 4 Xeons installed!!

--
Larry Samuels MS-MVP (Windows-Shell/User)
Associate Expert
Unofficial FAQ for Windows Server 2003 at
http://home.earthlink.net/~larrysamuels/WS2003FAQ.htm
Expert Zone - www.microsoft.com/windowsxp/expertzone
"Bill Crocker" <wcrocker007@comcast.net> wrote in message
news:Hb6dnQ7Hfr7XZgyiRVn-tg@comcast.com...
> Oops!!! I meant to say, it has two physical CPU's, and with
Hyperthreading
> enabled, it appears like four CPU's.
>
> Bill Crocker