Launching VS Profiler boosts Application Performance x20?

Question

EDIT 1
I do not exclude at all this might be caused by something very basic side effect of using the Profiler (some faulty setting in my \"regular\" pro

Answer 1

I've come across this many times... There is a very simple explanation for it. The profiler doesn't dispose objects, so the cost of object-disposal is not incurred while profiling.

Thus, if you want to improve performance to make it match the profiled performance, figure out where you're instantiating all these short-lived objects, and refactor the code.

I don't yet know of a really great way to immediately find the offending code, but I can help you narrow it down. If you profile your code, open the report, select "Functions" as your Current View, and then sort by Inclusive Samples, you will see the top methods... Your performance problem with object-instantiations is likely to be in one of those methods with the most Inclusive Samples.