JSI Tip 3542. How can I permanently set the processor affinity for an application?

In tip 0209, I describe how you can set the processor affinity on a running application.

In tip 2191, I described how bind devices to processors, to improve performance by more effectively using the processor's cache.

You can permanently set processor affinity for a non-operating system executable, on both Windows 2000 and Windows NT 4.0, by using the Imagecfg.exe tool from the supportdebugi386 folder of a Windows NT 4.0 CD-ROM, or the Imagecfg.exe tool from the Windows 2000 Server Resource Kit Supplement One.

NOTE: Do NOT use imagecfg on any kernel operating system files.

To permanently set the processor affinity for your 32-bit executable, open a CMD prompt and type:

imagecfg -a 0xn Pathyourprogram.exe

where 0xn is the affinity mask. The mask constrains your application to a specific CPU, from 0 - 31, where:

 CPU   MASK  0    0x1  1    0x2  2    0x4  3    0x8  4    0x10  5    0x20  6    0x40  7    0x80  8    0x100    etc

To set the affinity for "c:utilCountry Codes.exe" to processor 1, I typed:

imagecfg -a 0x2 "c:utilCountry Codes.exe"

and received the following response:

c:utilCountry Codes.exe contains no configuration informationc:utilCountry Codes.exe contains a Subsystem Version of 4.0c:utilCountry Codes.exe updated with the following configuration information:    Process Affinity Mask: 00000002

When I launch Country Codes.exe, its' affinity is set to CPU 1.