How to monitor method execution speeds

First, there is a class of development tools called Profilers. A good Profiler runs a software product under control and helps to find out performance bottlenecks very rapidly. The developer uses this information to improve performance of small fraction of performance critical code and runs it under the Profiler again.

You can try to perform your search to find appropriate Profiler. At this moment, I cannot give certain recommendations for a good .NET Profiler.

If you need to measure performance of the fragments of code only occasionally, you can create a simple home-baked ad-hoc "Profiler" using the class System.Diagnostics.Stopwatch:

System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch();

//..

stopWatch.Start();
//some code to time
stopWatch.Stop();

System.TimeSpan duration = stopWatch.Elapsed;

//don't use Millisecond which will be rounded to integer value;
//use TotalMilliseconds or TotalSeconds and the like:
double elapsedTimeMs = duration.TotalMilliseconds;

The class Stopwatch has much better accuracy compared to timer classes or System.DateTime class; this is the best class to measure performance.

—SA