I have recently been working with tracing performance and have posted several tidbits of information. Here is the overview.

1. Use TraceSource instead of Trace
2. Disable global locking
3. Clear the default listener in configuration
4. Don’t collect stacktrace information if not required
5. Create TraceSource instances once per name and cache for reuse. I have encountered memory leaks from creating large numbers of instances of the same TraceSource name.
6. Create a unique TraceSource and TraceListener for each logical part/tier/layer of the application (locking performance and data segregation)
7. Use thread safe listeners if possible
8. Check TraceSource.Switch.ShouldTrace before calculating any expensive information to provide to the trace message

On a side note, don’t forget to turn off code coverage for running load tests.