One run is not statistically significant %) Try running 10 times each, throw away the fastest and the slowest, indicate the average and min/max among the remain

One run is not statistically significant %) Try running 10 times each, throw away the fastest and the slowest, indicate the average and min/max among the remaining runs. Any random background processes might slow the system slightly during the initial run. A slightly better state of the page cache on the second run could play a role, too. Flushing the FS cache before each run might be a good idea; doing cat file.json > /dev/null could be an equally good idea.