number of processors

  • Thread starter Thread starter Tim
  • Start date Start date
T

Tim

I recently installed windows xp pro on a home made
system. Everything works OK except my control panel
shows I have a dual processor system when I only have one
Pentium 4 C. It also shows 22 IRQs when there should be
15. Will I need to reinstall windows to rid me of this
problem?
 
22 IRQ's is more or less normal for a computer with APIC (note: this is not
a typo of ACPI) support (your motherboard should support that).

Did you have both processors enabled when you installed windows? If so, I'm
surprised that Windows doesn't detect that you have two processors
installed. You may need to do a repair install to ensure that the correct
HAL is loaded.
 
You have hyperthreading CPU. It acts as though it is two
processors.

The extra "processor" has 7 IRQs for its functions.


| I recently installed windows xp pro on a home made
| system. Everything works OK except my control panel
| shows I have a dual processor system when I only have one
| Pentium 4 C. It also shows 22 IRQs when there should be
| 15. Will I need to reinstall windows to rid me of this
| problem?
|
 
Whoops... read your post wrong.

You have two logical processors in your CPU, as a result, it will show up as
two processors.
You want this (unless you like to pay for features and then not take
advantage of them).

The point about you having 23 interrupts (0 to 22) is still valid, it's
because your motherboard uses APIC.
 
The "C" is the key! If your MB supports Hyperthreading and it was on be
default (usual for HT capable boards with "c" CPUs) then it is picked up as
a 2nd "virtual" CPU making the system a "Multiprocessor" type.

The extra IRQ's are again "virtual" created by the APIC capabilities of the
MB. Most newer MBs have this capacity - many you can turn the option off in
CMOS. You can also do this (turn off in CMOS) for Hyperthreading. I would
leave both as they are - it will not hurt your system and may improve
performance!

FWIW,
Len
 
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