Setting Processor Affinity on Servers with Multiple CPUs

Applies To: Windows Server 2003, Windows Server 2003 with SP1

On a server with multiple CPUs, you can configure application pools to establish affinity between worker processes and CPUs to take advantage of more frequent CPU cache hits. By using processor affinity, you can control processors when applications place demands on system resources. Processor affinity is used in conjunction with the processor affinity mask setting to specify the CPUs.

Use processor affinity on computers with multiple processors when it is necessary to continue processing an application that is tied to a subset of the hardware in such a way that transitions from one processor to another are minimized. By default, processor affinity is disabled in IIS 6.0, and the load is distributed across all available CPUs. On a server that is supporting multiple applications, you can enable processor affinity so that a processor is dedicated to each application.

For information about how to set processor affinity, see Set Processor Affinity, or see the SMPAffinitized Metabase Property and the SMPProcessorAffinityMask Metabase Property.