How to estimate the thread context switching overhead?

Question

I am trying to improve the performance of the threaded application with real-time deadlines. It is running on Windows Mobile and written in C / C++. I have a suspicion that

Answer 1

Context Switch is expensive, as a rule of thumb it costs 30µs of CPU overhead http://blog.tsunanet.net/2010/11/how-long-does-it-take-to-make-context.html