Need help with getting Windows to use both cores of my Pentium D

Hi everyone!

I never tried to fix this before, but Windows (XP Pro w/ SP2 & all updates)
only shows one core from my Pentium D 805.

I checked Task Manager and have One CPU per graph, but only shows one graph.
Also, CPU-Z has the Processor Selection drop down grayed out. I also know
that I am only using one core because I use VMware and the virtual machines
only use one processor, but my physical processor can go up to 100% instead
of 50%.

I have the latest BIOS, ACPI is enabled, and POST shows "Count: 2" for my
CPU. Device Manager shows "ACPI Multiprocessor PC" and even shows 2
processors of "Intel(R) Pentium(R) D CPU 2.66GHz"!

I have also tried to set NUMPROC=2 in boot.ini, but that didn't work. I also
tried to do a repair install, but I still only saw one core.

I've searched on the internet for a possible solution, but couldn't find
one. I appreciate any help! Thanks.

Chris wrote:
Hi everyone!

I never tried to fix this before, but Windows (XP Pro w/ SP2 & all updates)
only shows one core from my Pentium D 805.

I checked Task Manager and have One CPU per graph, but only shows one graph.
Also, CPU-Z has the Processor Selection drop down grayed out. I also know
that I am only using one core because I use VMware and the virtual machines
only use one processor, but my physical processor can go up to 100% instead
of 50%.

Just a guess, but are you using VMware all of the time?


Yousuf Khan

No. I just used it as an example in my post. Why?

"Yousuf Khan" wrote in message
...
Chris wrote:
Hi everyone!

I never tried to fix this before, but Windows (XP Pro w/ SP2 & all
updates) only shows one core from my Pentium D 805.

I checked Task Manager and have One CPU per graph, but only shows one
graph. Also, CPU-Z has the Processor Selection drop down grayed out. I
also know that I am only using one core because I use VMware and the
virtual machines only use one processor, but my physical processor can go
up to 100% instead of 50%.

Just a guess, but are you using VMware all of the time?


Yousuf Khan

Yeah, halmacpi.dll. I also tried a fresh install which still showed 1 cpu,
and I tried Hotfix kb896256 on both my main os and the fresh os, but still
only 1 cpu. Any suggestions? Thanks.


"Yousuf Khan" wrote in message
...
Chris wrote:
No. I just used it as an example in my post. Why?

No, just thought perhaps VMware is masking out the second core with its
virtualization.

Do you know which HAL you're running?

How to force a Hardware Abstraction Layer during an upgrade or an
installation of Windows XP
http://support.microsoft.com/?kbid=299340

HAL options after Windows XP or Windows Server 2003 Setup
http://support.microsoft.com/kb/309283/

Chris wrote:
Yeah, halmacpi.dll. I also tried a fresh install which still showed 1 cpu,
and I tried Hotfix kb896256 on both my main os and the fresh os, but still
only 1 cpu. Any suggestions? Thanks.

No, sorry, that's all I could come up with.

So you're saying you see two processors listed when you boot at the
BIOS, but by the time the OS starts it's down to one processor?

Yousuf Khan

Yeah, but what is wierd is that Windows sees the 2 processors in Device
Manager and doesn't use them both... I tried a bunch of stuff and I still
cant figure out how to fix it.

"Yousuf Khan" wrote in message
s.com...
Chris wrote:
Yeah, halmacpi.dll. I also tried a fresh install which still showed 1
cpu,
and I tried Hotfix kb896256 on both my main os and the fresh os, but
still
only 1 cpu. Any suggestions? Thanks.

No, sorry, that's all I could come up with.

So you're saying you see two processors listed when you boot at the
BIOS, but by the time the OS starts it's down to one processor?

Yousuf Khan

I got the problem solved. I had to enable Hyper Threading in my BIOS. I
didn't think of it because the Pentium D 805 doesn't have HT, but now
Windows sees and uses both cores. Thanks for everyone's help!

weird!

"Chris" wrote in message
...
I got the problem solved. I had to enable Hyper Threading in my BIOS. I
didn't think of it because the Pentium D 805 doesn't have HT, but now
Windows sees and uses both cores. Thanks for everyone's help!

Chris wrote:
I got the problem solved. I had to enable Hyper Threading in my BIOS. I
didn't think of it because the Pentium D 805 doesn't have HT, but now
Windows sees and uses both cores. Thanks for everyone's help!

Interesting.

Yousuf Khan

Judd wrote:
weird!

I wonder if the Hyperthreading flag in the BIOS is more of a software
licensing feature than a technological feature? If the OS queries the
BIOS on startup and sees the HT flag is set, then it relaxes its
multiprocessor feature restrictions? If this is Windows XP Home, then
usually you should only be able to use one processor, but if it sees HT
being set in BIOS, then it allows multiprocessing.

Even AMD processors use the Intel Hyperthreading query flags when
displaying their multi-core processors, so it must be a standard
mechanism for figuring out multi-cores, mandated by Microsoft.
Microsoft told the two processor makers that this is the way it wants
it done.

Yousuf Khan