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Only 1 core reported

  • CPUs
  • Performance
  • Windows XP
  • Core
Last response: in CPUs
November 25, 2008 7:43:02 AM

I have an e5200 on an Asus P5kpl-am board overclocked to 3260mhz.

Real Temp, CPU z and XP's system performance only show 1 core. Does anyone know how I can see the other core?

Resetting BIOS and CMOS doesn't fix the problem. MSconfig only gives the option for 1 processor.

There is no entry for multiprocessor in the BIOS, although I think I saw this in the HAL options on WIndows setup (press F5 when setup asks for 3rd party SCSI and raid support).

When I installed XP I set the HAL to ACPI and not Multiprocessor ACPI. Is this the reason why I cannot see 2 cores? Will this affect the performance of the CPU, i.e. is my 5200 running at half its potential?

Changed the HAL to Standard PC but other core didn't register (didn't have an option to change it to multiprocessor).

If there is no performance hit then I don't think I will do a reinstall of Windows. I've only just got it running as I want it after a lot of stability problems initially with this PC's setup.

I'm guessing that my chip isn't just running on one core?! If it is, its doing a pretty splendid job all on its own.

Just looked (ctrl-f) through the pdf of the manual, doesn't mention multi processor.

Any ideas?



More about : core reported

November 25, 2008 8:20:55 AM

Had almost the same prob. try unistalling the acpi in safe mode, restart it and see if it installs the multiproc one. otherwise all i can think of is a format
November 25, 2008 8:39:36 AM

As far as my experience goes You can switch to uniprocessror if it is installed as multiprocessor but You cannot switch back to multiprocessor. You will need to reinstall windows.
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November 25, 2008 9:08:46 AM

Thanks for the help. I'll try the uninstall when I get home.

Is there a performance issue in this instance? I assume both cores are being utilised, but only one being shown in Windows.

November 25, 2008 9:13:52 AM

nope i would say one is being turned off... like in quads :) 
November 25, 2008 9:25:52 AM

November 25, 2008 1:45:40 PM

V3NOM said:
nope i would say one is being turned off... like in quads :) 

Is this true or a joke. Sorry if I don't get it.
a c 113 à CPUs
November 25, 2008 1:49:53 PM

lib319 said:
Is this true or a joke. Sorry if I don't get it.

It's no joke. Your CPU is only using one core.
a b à CPUs
November 25, 2008 1:58:07 PM

V3NOM said:
nope i would say one is being turned off... like in quads :) 

Interesting... Care to enlighten us?


Before getting radical and reinstalling the OS. Go to the device manager and "delete" the CPU. Then Restart. That should force the OS to treat it as a new device.
a b à CPUs
November 25, 2008 2:05:20 PM

Or right click and update driver in device manager sorted out my move from dual to quad.
a b à CPUs
November 25, 2008 2:14:45 PM

You can go from a single core processor to a multiprocessor without a Windows reinstall. I'm pretty sure of it anyway.
November 25, 2008 2:43:06 PM

shortstuff_mt said:
It's no joke. Your CPU is only using one core.



I'll try to change this in safemode and or delete the cpu as Scotteq said.

Works pretty well on 1 core I have to say

November 25, 2008 9:26:08 PM

Thanks to everyone for all the help. Reinstalled XP as a multiprocessor ACPI.

Got both cores reported now and my 3dMArk score has leapt up by over 1200.

Thanks again, appreciate it

December 9, 2008 5:01:02 AM

I think Venom is right, but anyway, try another utility for checking the CPU, as CPU-Z is japanese and maybe outdated.
December 9, 2008 5:46:47 AM

I was just saying some people turn off 3 cores of their quads to get a higher single OC sometimes...
a b à CPUs
December 9, 2008 9:17:51 PM

Which is really kind of stupid before the i7, because the Core 2 Quads can't actually disable the other cores, so disabling them will just prevent any work from being sent to them (but they'll still be on, just at idle). The i7 is different - it actually physically disables the cores that are shut off, and as a result, that strategy might work better.