Dual Xeons with Hyperthreading in XP?

G

Guest

Have just built a new system based on 2 x Xeon 3.2 GHz 800 FSB CPUs. They
are on an Asus NCCH-DL mainboard. Windows XP Pro only "sees" two logical
processors not four as expected. The BIOS sees both CPUs and recognises they
are hyperthreaded, but thats about it. Even the Intel utilities don't report
two physical processors are present. I get mixed results on hyperthreading &
the chipset utilities.

Can Win XP Pro support dual hyperthreaded processors (i.e. 4 logical
processors?) If so, how do I get Windows to recognise and report things
correctly?
 
J

Jim Macklin

Windows XP Pro does support hyperthreading, but a quick look
at Intel.com indicates that the Xeon DOES NOT support
hyperthreading, the only references I saw were to P4 with
hyperthreading.
Asus web site
http://www.asus.com/products/server/srv-mb/ncch-dl/overview.htm
doesn't mention hyperthreading either.


--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.



message
| Have just built a new system based on 2 x Xeon 3.2 GHz 800
FSB CPUs. They
| are on an Asus NCCH-DL mainboard. Windows XP Pro only
"sees" two logical
| processors not four as expected. The BIOS sees both CPUs
and recognises they
| are hyperthreaded, but thats about it. Even the Intel
utilities don't report
| two physical processors are present. I get mixed results
on hyperthreading &
| the chipset utilities.
|
| Can Win XP Pro support dual hyperthreaded processors (i.e.
4 logical
| processors?) If so, how do I get Windows to recognise and
report things
| correctly?
 
L

Leythos

Windows XP Pro does support hyperthreading, but a quick look at
Intel.com indicates that the Xeon DOES NOT support hyperthreading, the
only references I saw were to P4 with hyperthreading.
Asus web site
http://www.asus.com/products/server/srv-mb/ncch-dl/overview.htm doesn't
mention hyperthreading either.
Click to expand...

I hate to say this, but MY XEON Boards and Windows 2003 Server support HT,
in fact, I can see the difference between HT ON and HT Off in some
applications.

XEON's in the P4 era, fully support HT.
 
J

Jim Macklin

I looked at the two web sites I mentioned and they did not
cite hyperthreading, except for the P4.
Perhaps you can help the OP since you have a system working.
He is using XP Pro and you have Windows 2003 Server,
Perhaps the OP should run EVEREST and get the exact model
numbers for his system components and check for the settings
he needs in the BIOS, and then reinstall his system after
the function is enabled in the BIOS.
With two CPUs the OP should be seeing 4 processors. XP Pro
does support dual processors, I wonder if the OP is mistaken
and using XP Home?



| On Wed, 27 Apr 2005 00:40:07 -0500, Jim Macklin wrote:
|
| > Windows XP Pro does support hyperthreading, but a quick
look at
| > Intel.com indicates that the Xeon DOES NOT support
hyperthreading, the
| > only references I saw were to P4 with hyperthreading.
| > Asus web site
| >
http://www.asus.com/products/server/srv-mb/ncch-dl/overview.htm
doesn't
| > mention hyperthreading either.
|
| I hate to say this, but MY XEON Boards and Windows 2003
Server support HT,
| in fact, I can see the difference between HT ON and HT Off
in some
| applications.
|
| XEON's in the P4 era, fully support HT.
|
| --
| (e-mail address removed)
| remove 999 in order to email me
|
 
L

Leythos

I looked at the two web sites I mentioned and they did not cite
hyperthreading, except for the P4. Perhaps you can help the OP since you
have a system working. He is using XP Pro and you have Windows 2003
Server, Perhaps the OP should run EVEREST and get the exact model
numbers for his system components and check for the settings he needs in
the BIOS, and then reinstall his system after the function is enabled in
the BIOS.
With two CPUs the OP should be seeing 4 processors. XP Pro does support
dual processors, I wonder if the OP is mistaken and using XP Home?
Click to expand...

Most of my servers have Dual or Quad 2.4ghz Xeon CPU's and show as 4 or 8
CPU's. I don't have any Dual XP Prof workstations, but since XP supports 2
CPU's I would only expect it to show 2 CPU's on a Dual Xeon box.

What we need is someone using XP Prof and running Dual Xeon CPU's to tell
us what they see.
 
J

Jim Macklin

Found this link on the bottom, the very bottom, of the page
you linked...
http://support.intel.com/business/bss/products/hyperthreading/server/ht_server.pdf

It doesn't seem to be a big marketing push.


http://support.microsoft.com/default.aspx?scid=kb;en-us;810231

http://support.intel.com/support/processors/sb/CS-007880.htm


message
| Jim,
|
| Yes the current 800 Mhz FSB XEONs do support HT. Have a
look at the XEON
| 800 FSB link at this Intel page:
|
| http://support.intel.com/design/Xeon/documentation.htm
|
| Does anyone know if where there is an official reference
to Win XP Pro being
| capable of recognising 2 x HT processors, ie 4 logical
ones?
|
| "Jim Macklin" wrote:
|
| > Windows XP Pro does support hyperthreading, but a quick
look
| > at Intel.com indicates that the Xeon DOES NOT support
| > hyperthreading, the only references I saw were to P4
with
| > hyperthreading.
| > Asus web site
| >
http://www.asus.com/products/server/srv-mb/ncch-dl/overview.htm
| > doesn't mention hyperthreading either.
| >
| >
| > --
| > The people think the Constitution protects their rights;
| > But government sees it as an obstacle to be overcome.
| >
| >
| >
| > message
| >
| > | Have just built a new system based on 2 x Xeon 3.2 GHz
800
| > FSB CPUs. They
| > | are on an Asus NCCH-DL mainboard. Windows XP Pro only
| > "sees" two logical
| > | processors not four as expected. The BIOS sees both
CPUs
| > and recognises they
| > | are hyperthreaded, but thats about it. Even the Intel
| > utilities don't report
| > | two physical processors are present. I get mixed
results
| > on hyperthreading &
| > | the chipset utilities.
| > |
| > | Can Win XP Pro support dual hyperthreaded processors
(i.e.
| > 4 logical
| > | processors?) If so, how do I get Windows to recognise
and
| > report things
| > | correctly?
| >
| >
| >
 
V

V Green

Leythos said:
Most of my servers have Dual or Quad 2.4ghz Xeon CPU's and show as 4 or 8
CPU's. I don't have any Dual XP Prof workstations, but since XP supports 2
CPU's I would only expect it to show 2 CPU's on a Dual Xeon box.

What we need is someone using XP Prof and running Dual Xeon CPU's to tell
us what they see.
Click to expand...

You got it.

Running 2.8G Xeons/533 on an ASUS PC-DL.

4 processors shown in Device Manager.

Problems of the OP's type are often caused by NOT having HT
turned on in the BIOS before installing XP. If HT is off, XP will
not install the correct HAL for the system.
 
L

Leythos

Problems of the OP's type are often caused by NOT having HT turned on in
the BIOS before installing XP. If HT is off, XP will not install the
correct HAL for the system.
Click to expand...

But if it's turned OFF before install, and he has two physical CPU's (not
logical) then the ACPI Multi kernel is installed by default - HT would be
available IF the two CPU's were installed during the XP install even if HT
was disabled.

If the second CPU was added after the install, and HT was disabled all
along, then the update to the ACPI Multi kernel would be needed.
 
V

V Green

Leythos said:
But if it's turned OFF before install, and he has two physical CPU's (not
logical) then the ACPI Multi kernel is installed by default - HT would be
available IF the two CPU's were installed during the XP install even if HT
was disabled.

If the second CPU was added after the install, and HT was disabled all
along, then the update to the ACPI Multi kernel would be needed.
Click to expand...

I know, it doesn't make sense.

All I can say it that in the past, when this happened to
some other users, HT was turned OFF in the BIOS, and
when it was turned ON, and XP was reinstalled, all was well.

Go figure. Perhaps a mgfr.-specific BIOS issue.
 
P

Peter Foldes

Yes he should run Everest. I have P4 dual Xeon 3.0 with hyperthreading and
using W2K3 and Everest reports as such.
 
G

Guest

I reply to a bunch of queres raised, some updates and notes.

Definately playing with Win XP Pro (OEM).
HT was enabled during XP installation.
After XP installation, saw 2 CPUs whether HT was turned on or off.
Am convinced Win XP Pro should be able to handle 2 physical/4 logical CPUs
Have recently tried Win Server 2003, still only 2 CPUs showing.
Suspect a faulty mainboard. Both chips work fine but can't run Asus NCCH-DL
board without a chip in socket 1. Maybe socket 2 is faulty.
Asus website no help whatsoever.....

V Green said:
Leythos said:
But if it's turned OFF before install, and he has two physical CPU's (not
logical) then the ACPI Multi kernel is installed by default - HT would be
available IF the two CPU's were installed during the XP install even if HT
was disabled.

If the second CPU was added after the install, and HT was disabled all
along, then the update to the ACPI Multi kernel would be needed.
Click to expand...

I know, it doesn't make sense.

All I can say it that in the past, when this happened to
some other users, HT was turned OFF in the BIOS, and
when it was turned ON, and XP was reinstalled, all was well.

Go figure. Perhaps a mgfr.-specific BIOS issue.
Click to expand...
 

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