We are running an HP ProLiant Windows Server 2008 R2 SP1 and IIS 7.5 on a dual CPU Xeon system (16 cores per CPU). The web site is a ASP.NET 4.5 running in a App-pool using a a classic managed pipeline.
When I load test our application only one CPU is loaded. The other stays CPU flat, i.e. it is using 16 cores of available 32.
I checked the Affinity option in the app pool settings in IIS and it is False.
I then checked the Affinity for the w3wp.exe process in the Task Manager and it displayed two processor groups: "Group 0" and "Group 1".
All cores were checked in "Group 0" but none in "Group 1". When I tried selecting all in "Group 1" the setting wouldn't save (it just opened up unselected when I checked "Set affinity ..." again.)
Is IIS able to handle dual processors for a single app pool? Is there a missing setting I need to set? Any ideas?