Every process and thread in Windows gets an affinity mask which defines which processors it can run on. Process Explorer 12.09 has an interface for changing process affinity mask, but does not allow one to manipulate the thread affinity.
So I got an excuse to write cpuc1 to query and change affinity right down to an individual thread from command line. cpuc is capable of setting the thread ideal cpu as well.
Here is a dump of command line options to cpuc.
Although I have an Itanium download of this tool, I have not tested this on Itanium. If you have access to big iron Itanium (or amd64) machines, I would appreciate your feedback.
You can get cpuc from downloads area.