Is it possible to instrument .NET BCL, ASP.NET, WCF or ADO.NET assemblies?

I want to diagnose some performance issue related to entity framework but at the moment I'm getting only large numbers on System.Linq.Queryable. Can I somehow configure VS Studio 2010 Ultimate to include referenced .NET assemblies in profiling / instrumentation? I downloade开发者_运维问答d .NET 3.5 soruces and symbols and tried to allow their debugging but it didn't help.

You cannot modify signed assemblies, and this includes instrumenting .Net assemblies. But sample profiling can take you a very long way and is non-invasive (does not require instrumentation).