All of the IIS process’s show up as the same process name, which makes it really challenging to figure out which of your websites has lost it’s mind. In order to trace an IIS website or application pool back to a PID, you just need to open a command prompt and run the iisapp utility.
iisapp
Outputs
W3WP.exe PID: 7424 AppPoolId: Site1
W3WP.exe PID: 8096 AppPoolId: JoesSite
W3WP.exe PID: 13080 AppPoolId: Wookielove.com
And now you can just use taskmanager to track resource usage to a site.