Every 7.8μs your computer’s memory has a hiccup
&gt;clock_gettime(CLOCK_MONOTONIC, &amp;ts);<p>IIRC this call has an overhead of a few ns. Isn&#x27;t that close to or even higher than the time it takes to perform the action being measured on every loop? If so the author is just measuring clock_gettime. It can be confirmed on the author&#x27;s system by simply calling clock_gettime without calling the measured action (movntdqa &#x2F; cache flush) and comparing the results. An alternative approach is to call clock_gettime before and after the loop, not on every iteration, and then take an average.