[j_not_j]

And he didn't repeat each test case 5 or 9 times, and take the median (or even an average).

There will be operating system noise that can be in the multi-percent range. This is defined as various OS services that run "in the background" taking up cpu time, emptying cache lines (which may be most important), and flushing a few translate lookaside entries.

Once you recognize the variability from run to run, claiming "1%" becomes less credible. Depending on the noise level, of course.

Linux benchmarks like SPECcpu tend to be run in "single-user mode" meaning almost no background processes are running.