Two CPUs in Device Manager

[Don Phillipson]

Recent unexplained system hangs (associated with audio?)
led me to study the Hardware Device Manager where I was
surprised to see two CPUs, apparently identical. This
ASUS P4 mb (2006) has only one (2.8 GHz, 1 Gb RAM).

Deleting one of these precipitated worse failures to boot:
but things now appear OK (e.g. no tell-tale crackle during
startup chimes) after button reset
to F8 Advanced Options menu "Safe Mode"
which generated "System Settings Changed -- Restart?"
accepted OK, restarted (Normal mode), now running OK.

But Dev. Mgr. still shows 2 CPUs (although early today
I "uninstalled" one for lack of options Delete or Remove.)

Does this mean anything? Does it matter?

 

[Paul]

Recent unexplained system hangs (associated with audio?)
led me to study the Hardware Device Manager where I was
surprised to see two CPUs, apparently identical. This
ASUS P4 mb (2006) has only one (2.8 GHz, 1 Gb RAM).

Deleting one of these precipitated worse failures to boot:
but things now appear OK (e.g. no tell-tale crackle during
startup chimes) after button reset
to F8 Advanced Options menu "Safe Mode"
which generated "System Settings Changed -- Restart?"
accepted OK, restarted (Normal mode), now running OK.

But Dev. Mgr. still shows 2 CPUs (although early today
I "uninstalled" one for lack of options Delete or Remove.)

Does this mean anything? Does it matter?

I have a dual core processor, and under "Processors" in
Device Manager, I have two entries.

Intel Core2 Duo CPU E8400 @ 3.00GHz
Intel Core2 Duo CPU E8400 @ 3.00GHz

And physically, those are two cores on the same silicon die.
They rest in the same LGA775 socket. A single socket motherboard.

I'd say what you're seeing is normal. Your processor could be
a Northwood with FSB800, and Hyperthreading. A lot of the
FSB800 processors have Hyperthreading. If Hyperthreading
was enabled in the BIOS, when you did your install, the
"Computer" entry in Device Manager should say

ACPI Multiprocessor PC

Also, when you look in Task Manager, you might see two
graphs for the CPU performance. It is possible to set
Task Manager to make one (combined) graph, but equally
well, you should have the ability to make a graph for
each core.

You can disable Hyperthreading in the BIOS, which will
cause the OS to show only one entry in Device Manager.
I don't know if the OS will immediately change the
HAL to ACPI Uniprocessor PC on its own or not. It might
remain set to Multiprocessor, even if there is only
the one core still running.

If it was my system, I'd be more interested in carefully
reviewing the BIOS entries, because something could be
unhinged. Some of those old boards have "MPS Spec 1.1 or
1.4", and I set that to 1.4. They may mention ACPI 2.0
and I select that standard. The ACPI options may include
"S1 & S3" - don't change that unless you want to be spending
time later with the "dumppo" utility in Windows to finish
the job. Your motherboard is probably too modern for
"Delayed Transaction" setting, but if you have one,
it should be enabled. "Delayed Transaction" helps prevent
sound crackle caused by a data underrun on the sound
subsystem - it's an optimization for the operation of the
PCI bus. That, and setting PCI Latency to perhaps a value
of 32. PCI Latency is a tradeoff between bus
efficiency, and fairness for delay sensitive devices
like the sound card.

Delayed Transaction (BIOS Setting)
http://www.techarp.com/showFreeBOG.aspx?lang=0&bogno=58

(More BIOS info...)
http://www.techarp.com/freebog.aspx

With the older motherboards, enabling Delayed Transaction
and fiddling with PCI Latency, could kinda fix up the sound.
The best test case for sound, is when Windows plays its
welcome tune during boot. There is a nice combination
of severe disk activity, along with sound playback,
and if the hardware hasn't been tuned just right with
the BIOS settings, you get snap, crackle, pop from the
speakers.

HTH,
Paul

 

[VanguardLH]

Recent unexplained system hangs (associated with audio?)
led me to study the Hardware Device Manager where I was
surprised to see two CPUs, apparently identical. This
ASUS P4 mb (2006) has only one (2.8 GHz, 1 Gb RAM).

Deleting one of these precipitated worse failures to boot:
but things now appear OK (e.g. no tell-tale crackle during
startup chimes) after button reset
to F8 Advanced Options menu "Safe Mode"
which generated "System Settings Changed -- Restart?"
accepted OK, restarted (Normal mode), now running OK.

But Dev. Mgr. still shows 2 CPUs (although early today
I "uninstalled" one for lack of options Delete or Remove.)

Does this mean anything? Does it matter?

You never identified the model of the CPU, just some specs. Could be
you have a dual-core CPU. Could be you have a single-core CPU but with
hyperthreading enabled (http://en.wikipedia.org/wiki/Hyper-threading).

 

[Don Phillipson]

Recent unexplained system hangs (associated with audio?)

led me to study the Hardware Device Manager where I was
surprised to see two CPUs, apparently identical. This
ASUS P4 mb (2006) has only one (2.8 GHz, 1 Gb RAM).

1. Persistent system hangs now appear solved -- by hardware
(a new mouse: my last Logitech 3-button mouse was at least
a decade old, perhaps 20 years.) Warning sign of impending
crash was chatter in audio (listening to BBC via Internet.) I
cannot imagine why a dud mouse would have this effect but
it seems so. IIRR this happened years ago (when my last
Logitech trackball was dying.)

2. I had not known a single CPU hyperthreaded (via BIOS)
would show in Device Mgr as two identical CPUs -- so I am
so glad this NG is still alive !

 

[pjp]

1. Persistent system hangs now appear solved -- by hardware
(a new mouse: my last Logitech 3-button mouse was at least
a decade old, perhaps 20 years.) Warning sign of impending
crash was chatter in audio (listening to BBC via Internet.) I
cannot imagine why a dud mouse would have this effect but
it seems so. IIRR this happened years ago (when my last
Logitech trackball was dying.)

2. I had not known a single CPU hyperthreaded (via BIOS)
would show in Device Mgr as two identical CPUs -- so I am
so glad this NG is still alive !

My understanding is it's XP-Pro only and home won't do the multi-processer
thing. Unsure about later OS's.

 

[Bob Willard]

My understanding is it's XP-Pro only and home won't do the multi-processer
thing. Unsure about later OS's.

IIRC, XP Home does support HT CPUs, but it does not support dual CPUs;
that requires XP PRO. I don't recall if XP Home supports dual CPUs on
the same die; when XP appeared, dual CPUs meant dual sockets, and that
capability was reserved for XP PRO.

 

[SC Tom]

IIRC, XP Home does support HT CPUs, but it does not support dual CPUs;
that requires XP PRO. I don't recall if XP Home supports dual CPUs on
the same die; when XP appeared, dual CPUs meant dual sockets, and that
capability was reserved for XP PRO.

My XP Home SP3 32-bit shows two entries under Processors, both the same, AMD
Athlon(tm) 64 X2 Dual Core Processor 4800+. Task Manager also shows graphs
for 2 CPU's, and if I Set Affinity on a running process, I have the choice
of CPU0 and/or CPU1. So it will support a dual core (not using
HyperThreading), but may not support two separate CPU's. Seems to me, years
ago, I tried to install XP Home on one of our spare dual CPU PC's at work,
and it failed miserably. But, as you stated, XP Pro installed and ran fine
on it.

 

[Paul]

IIRC, XP Home does support HT CPUs, but it does not support dual CPUs;
that requires XP PRO. I don't recall if XP Home supports dual CPUs on
the same die; when XP appeared, dual CPUs meant dual sockets, and that
capability was reserved for XP PRO.

There was a change in licensing scheme.

For Win2K, the scheme was core based. For example, if I purchased a
quad core (single socket) processor, my copy of Win2K was only licensed
for 2 cores.

When WinXP came out, the license changed to sockets.

http://en.wikipedia.org/wiki/Windows_xp

"Multiprocessor limits

The maximum quantity of physical processors of a PC that Windows XP
supports is: two for Professional, one for Home Edition. This count
refers to the entire physical processor socket, not the individual cores
of a multi-core processor."

So, two sockets for Pro and one socket for Home. If you want to use
a Q6600 Quad Core, Home would support all four cores, because they
all live on a single socket. Since you can buy a processor now, with
ten cores living on a single socket, that would be an (impractical)
limit for Home. The ten core processor is expensive. If you can afford
one, you can afford decent software too.

There are some ten core processors in this list, for $4000.00 . You can
run a single one of these, with your copy of Windows XP Home

http://ark.intel.com/ProductCollection.aspx?codeName=33175&code=westmere-ex

When the Westmere-EX is running, you'll see twenty graphs in the
Task Manager, as the models support Hyperthreading as well.

Paul