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

interesting. xp Pro on install will automatically detect processors, even
for hyperthreading cpu, it show 2 CPU. So you may want to find some test to
see if the second core is still good or just Xp not finding it.

look at the bios setting also - making sure both are enabled

"Chris" wrote in message
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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.

"Yousuf Khan" wrote in message
ups.com...
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


Really? That's interesting.... I've played with Managed C++ libraries that
allow my applications to tell the difference (if there's a need), so I'm
guessing this isn't to fool windows... Perhaps more just to point out there
aren't multiple sockets?

Carlo Razzeto wrote:
Really? That's interesting.... I've played with Managed C++ libraries that
allow my applications to tell the difference (if there's a need), so I'm
guessing this isn't to fool windows... Perhaps more just to point out there
aren't multiple sockets?

I read the Hyperthreading specs about 99 years ago, so going from
memory, I think I recall that there is a query which can tell you how
many cores there are and how many processors there are. The HT spec
allows you to have upto 255 cores per processor, but all of those
processors have to have an identical number of cores to each other.

Yousuf Khan