C++ and accurate timers under Linux?

[gnusci]

Brilliant! You took the number of seconds that a process executed and multiplied by a 1000 to yield milliseconds. Now why didn't I think of that?

Thanks dwhitney67... I just wanted to give the correct output to the OP, but actually your solution was fine, since the OP can straight forward get the seconds.

[Npl]

What brought you to the conclusion that clock() uses RTC? According to a man page for clock(), the function measures time spent in the process with an accuracy dependent on the implementation of the function.

I somehow mixed it up with the time() function. My apologies.

[MimeNarrator]

I see that this thread is long dead, but for future googlers who come across it as I did in their search for an accurate way to compare execution times in C or C++, a very simple solution is provided by the cycle.h file included with the source code for FFTW, available at http://www.fftw.org. It can be included in any program (subject to FFTW's license) independently from the rest of FFTW, and implements a tick counter using inline assembly provided for many different architectures.