Dissable Multiprocessor

[HeresyDW]

Hi,
We're trying to troubleshoot a crashing problem that we are now 95 percent sure is caused by using a multiprocessor system.

The system we are using is an Asus PC-DL Deluxe with two 3 Ghz processors and we can not eliminate the crashing on this machine, but several single processor machines do not have any problems with the application we are using.

Is there any way to dissable multiprocessor support on a multiprocessor motherboard?

Or is it possible to force Windows to use only one processor?

Any help would be appreciated.

 

[johnjkr1]

Pull out one of the extra cpu's?

 

[HeresyDW]

If I pull out one of the processors, will I have to reinstall Windows 2000 Pro?

 

[johnjkr1]

That is a good question...they use a different hal or kernal....i found this:

http://www.tipsdr.com/windows2000tips.html

"You can easily go from uniprocessor (UP) to multiprocessor (MP) support in Windows 2000 by using the Device Manager.
Here's how to do this in Windows 2000:
In Control Panel, open System, choose the Hardware tab, then click the Device Manager button.
Select the Computer node and expand it.
Double-click the first object listed below the computer node?on some systems, it is called "Standard PC". It might have a different name on your particular system.
Choose the Driver tab, and then click the Update Driver button.
On the Upgrade Device Driver Wizard, click the Next button, then select "Display a known list of drivers for this device so that I can choose a specific driver." Click the Next button.
On the Select Device Driver page, select "Show all hardware of this device class."
Select the HAL that matches your new configuration, multiprocessor or uniprocessor. Click the Next button. Check that the wizard is showing the configuration you want.
To install the driver, click the Next button.
To complete the wizard, click the Finish button.
Note: To switch from uniprocessor (UP) to multiprocessor (MP) support in Windows NT 4.0, use a Resource Kit utility called uptomp, or reinstall the operating system."


So it doesnt sound like it really simple. Perhaps you should investigate why the 2 proc machine is crashing. Did it have a clean install, or was it ghosted with an OS. Can you provide any specifics on the crashing? (blue screen, reboot, different apps,etc.)

 

[HeresyDW]

Thanks for that info. We are going to give that a try and switch from MultiProcessor to Uniprocessor in Win2k.

The application that is crashing is a custom built Machine Vision system programmed using National Instuments LabView. We have had issues with National Instruments products crashing before on multiprocessor systems (ieee 1394 driver). With this new problem we have engaged National Instruments, however it may take them some time to correct the issue, so we're looking for interim solutions to the problem short of swapping hardware.

Thanks again, I've got my fingers crossed.

 

[johnjkr1]

Yeah, i figured it was a special app like that, normally multi-proc systems are fairly stable

 

[Slikkster]

Changing the HAL via Device Manager is not supported by MS, as far as I recall. Yes, can be done, but can also lead to other issues.

There appears to be an easier way to experiment, and it only involves using a "switch" at bootup. There's a switch for the boot.ini file labeled "/ONECPU", which only enables one cpu out of a multiprocessor system. You'd simply have to edit the line in boot.ini that's loading your operating system and add that switch.

There's also another switch labled "/NUMPROC=n" where "n" would indicate enabling the first "n" processors in a multiprocessor system.

If it's not too late, I'd go the boot.ini route to test that application.

 

[mastertech01]

Have you simply tried setting processor affinity to that application when running?

Open Task Manager and select your application on the Processes tab. Right click the program name and choose Set Affinity. Uncheck the processors which should not run this application

 

[Slikkster]

See, there ya go...something even easier and less invasive/system altering.

 

[HeresyDW]

It's too late!!!

We tried switching the HAL and that fixed the problem, and on the surface doesn't appear to cause any other problems.

Thanks for the other suggestions, we'll also give those a try as we have a second machine running the same applications.

Thanks again for all the good info.

 

[Slikkster]

Sure is a waste of a cpu, though...I'll give ya $25 for it