How to Use Specific CPU for a Specific Application in Windows Vista

Earlier users were confined to the use of only one CPU in their computer system. One CPU was not sufficient to handle large applications and let to large wait times for executing a CPU hungry task. This problem of long waiting time led to the development of new CPU's called the Dual CPU's. Dual CPU's further led to the development of new advanced version referred to as Core2Duo or Conroe CPU. In the new architecture of CPU, two CPU's were embedded into one thus providing the power of 2 CPUs in 1.

However, windows XP was not designed to handle such CPUs and as such was unable to fully utilize the power of Dual Core and Core2duo CPUs. This issue was addressed in Windows Vista and it was made sure that the power of Dual Core and Core2Duo or Conroe CPUs could be utilized to its full extent.

This is one of the most amazing features of Windows Vista that allows you to use a specific CPU for an application. You can assign one CPU to one application and other CPU for other application or you can assign both CPUs to a single application thereby reducing the overall processing time. This feature is only accessible if you are using a Dual Core or Core2Duo or a Quad Core CPU.

In order to enable this feature, you will have to pass the affinity flag to the start utility in command prompt. For example, if you want to use CPU0 to paint brush, then type the following command at the 'Command Prompt' window:

c:windowssystem32cmd.exe /C start /affinity 1 mspaint.exe

You will notice that CPU0 is assigned to paint brush application.

To assign the same application to another CPU, you can use the following command:

For CPU0

/affinity 1

For CPU 1, use this switch:

/affinity 2

You can assign different CPUs to different application depending on the number of cores in your CPU.

If you feel uncomfortable with commands then you can also do it manually. In order to manually assign CPUs, start the application and then press Ctrl + Alt + Del keys together to start the 'Taskbar Manager'. From the 'Taskbar Manager' window, select the desired process from the 'Processes' and right click on it. From the pop-up menu, select 'Set Affinity' and select either CPUs or both according to your wish. This way you will be able to utilize the maximum power from your CPU for processor hungry applications.