|It is important to understand what setting affinity actually does. It restricts the process to using only the selected processor (or core). It does not in any way reserve the processor as Windows will continue to use it for whatever other processes it wishes, subject of course to other affinity restrictions. Windows assigns an ideal processor to each thread but this is only a guide. It may use others if the ideal processor is busy. If an affinity restriction prevents this the process will just have to wait. From a performance standpoint that is not normally a good thing.|
Setting an affinity restriction is more likely to impair a processes performance than improve it. Of course there are exceptions.