Resolution of std::chrono::high_resolution_clock doesn't correspond to measurements

I'm going to guess you are using Visual Studio 2012. If not, disregard this answer. Visual Studio 2012 typedef's high_resolution_clock to system_clock. Sadly, this means it has crappy precision (around 1 ms). I wrote a better high-resolution clock which uses QueryPerformanceCounter for use in Visual Studio 2012...

HighResClock.h:

    struct HighResClock
    {
        typedef long long                              rep;
        typedef std::nano                              period;
        typedef std::chrono::duration<rep, period>     duration;
        typedef std::chrono::time_point<HighResClock>  time_point;
        static const bool is_steady = true;

        static time_point now();
    };

HighResClock.cpp:

namespace
{
    const long long g_Frequency = []() -> long long
    {
        LARGE_INTEGER frequency;
        QueryPerformanceFrequency(&frequency);
        return frequency.QuadPart;
    }();
}

HighResClock::time_point HighResClock::now()
{
    LARGE_INTEGER count;
    QueryPerformanceCounter(&count);
    return time_point(duration(count.QuadPart * static_cast<rep>(period::den) / g_Frequency));
}

(I left out an assert and #ifs to see if it's being compiled on Visual Studio 2012 from the above code.)

You can use this clock anywhere and in the same way as standard clocks.

The resolution of a clock is not necessarily the same as the smallest duration that can be represented by the data type the clock uses. In this case your implementation uses a data type which can represent a duration as small as 100 nanoseconds, but the underlying clock doesn't actually have such a resolution.

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The low resolution of Visual Studio's high_resolution_clock has been an issue for several years. Microsoft's C++ standard library maintainer, Stephan T. Lavavej, has indicated that this has been fixed in Visual Studio 2015 via the use of QueryPerformanceCounter().