asynchronous - C# Stopwatch to time an async/await method inaccurate -

i'm writing performance tests, , want able time method asynchronous. code looks this, action func<task<httpresponsemessage>>:

var sw = new stopwatch(); httpresponsemessage response = null;  sw.start(); response = await action().configureawait(continueoncapturedcontext: false); sw.stop(); 

the code compiles , runs ok, measured milliseconds 100 times higher request timings see in fiddler - fiddler reports 200-300ms, stop watch reports ~30,000ms. there catch timing asynchronous methods? solution timing in action (which annoying?)

this should work fine measuring true amount of time takes asynchronous task finish. need keep in mind that:

1. the time measuring fiddler measuring request only, , non of time takes code process response.
2. there significant difference in time here , should able time code see how long takes progress break point before request after request. if closer 30 seconds stop watch accurate.
3. there isn't obvious me make time inaccurate.