So there are a couple different things that can affect performance of your ASP.NET application. One of them is if you are running with debug builds of your files. This is where this command comes in. When run, it will tell you any modules that you have in your process that are built debug or built release with the /debug switch (to create pdb files).
The output looks like:
So from this you can see what files you need to rebuild. Remember that unless you are debugging in Visual Studio, you don’t need pdb files for .NET. So you can safely turn that switch off.