Requests/Sec vs Requests Executing

I am load testing a WCF service and I am having a hard time analyzing the results. The web service is running on IIS 7.0, Windows Server 2008 standard 64 bits. I test with a load of 1,000 requests every 3 seconds for a duration of 1 minute. In perfmon ASP.NET Requests/Sec is going up to 500 but ASP.NET Requests Executing does not go over 20. There are no requests queuing and the Request Execution Time is around 2 msec. CPU for IIS and db machines are stable at 10-15%, so I don’t have any issues there. The service application pool is running under开发者_开发知识库 an Integrated pipeline with v2.0 .net framework.

I am trying to understand the difference Requests/Sec and Requests Executing, and how can I increase the Requests Executing.

Thanks