Below are a few links that I found about Profiling Performance of ASP.NET Code
Code performance analysis in Visual Studio 2008 and Find Application Bottlenecks with Visual Studio Profiler
* Tool : VSProfiler - Analyze Performance of Managed Code
How To: Use CLR Profiler and Transcript: Profiling Managed Code with the CLR Profiler are talking about CLR memory allocation profiler.
* Auto Performance Tuning in ASP.NET 2.0 process model (processModel) section of machine.config comes with default value of autoconfig="true".
and details in MSDN article Contention, poor performance, and deadlocks when you make Web service requests from ASP
We've downloaded evaluation version of ANTS Profiler(cost from $395). Looks very good.
My other post IIS Set Expiration Dates adds the expiration header only to static content has a few links, how to optimize web sites