How to realise long-term high-resolution timing on windows using C++?

Question

I need to get exact timestamps every couple of ms (20, 30, 40ms) over a long period of time (a couple of hours). The function in which the timestamp is taken is invoked as a

Answer 1

You'll be hard pressed to find anything better than QueryPerformanceTimer() on Windows.

On modern hardware it uses the HPET as a source which replaces the RTC interrupt controller. I would expect QueryPerformanceTimer() and the System clock to be synchronous.