This question was asked on another thread, here is what Chris Peters had to say. "Yes it is possible to disable cores...... I've heard of this and also checked with our technology team. This core disable is done through BIOS and each system vendor makes their own BIOS's, and may or may not have this option. So there is not any standard documentation (sorry). Some server system vendors have a BIOS option which is “Disable AP” (Disable application processor). When this option is “enabled”, one core on each die is disabled. Other vendors may have the option, but called it something else."
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I second Chris here that disabling cores on a multi-core system is possible. Let me show you how, say you are using Windows XP Pro, here's what you do:
Right click on "My Computer" -> Properties -> Advanced -> Startup & Recovery;
There, you will find a button named "edit" - by pressing it you can edit the Windows "Boot.ini" file manually. (Make sure you make a copy of this file before you edit it)
At the end of the line in boot.ini file, add the following code: /numproc=1
This would limit your system to one core, likewise if you want to limit it to 2 or 3, you can change the number instantly.
Save the Boot.ini file and reboot your computer.
Your Windows XP will now only use one Processor Core.
Furthermore, you can also limit your running applications to use all 4 or any lesser number of cores (ref: quad-core) on the fly but this is a temporary solution and will be only applicable on a process as long as the OS is running, once rebooted or shutdown ... the process will again use all cores. All you have to do is:
Press ALTShiftESC to bring up the task manager
Select the SERVICES TAB to bring up a list of services currently running on your computer.
Select a specific task you want to limit to a number of core usages and right click on it.
Select SET AFFINITY and uncheck the number of cores that are not required (by default all would be selected).
Click OK and then close the task manager.
That very process will now be using the number of cores you have selected.
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