Std :: chrono doesn't seem to give exact resolution / frequency

Question

I read about it and the numbers don't add up. On my operating system (Windows), I can check the resolution of the system clock as follows:

LARGE_INTEGER largeInt; // Basically a struct/union containing a long long
QueryPerformanceFrequency(&largeInt);
// largeInt now holds the frequency of my system clock, it 3903987
// This ends up being a resolution of about 256 nanoseconds

Everything is fine, but now I want to use std :: chrono to check the same details. According to cppreference.com and the popular answer on this site, the std :: chrono clock period is a compilation time coefficient consisting of a numerator and a denominator that determines how many seconds are between ticks.

cppreference.com:

period: a std :: relation representing the tick period (i.e. the number of seconds per tick)

And from the answer:

The minimum representable duration is high_resolution_clock :: period :: num / high_resolution_clock :: period :: den seconds. You can print it like this:

std::cout <<
(double)std::chrono::high_resolution_clock::period::num /   
std::chrono::high_resolution_clock::period::den;

So I tried:

// On Windows the result is typedeffed as intmax_t, which is a typedef for a long long
    intmax_t numerator = std::chrono::high_resolution_clock::period::num;
    intmax_t denominator = std::chrono::high_resolution_clock::period::den;
    // numerator is 1 and denominator is one billion, which would suggest a 
    // tick period of one nanosecond?

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Answer 1

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