Your benchmark lied: why modern CPUs make measurements meaningless
Same benchmark, same JVM, nothing changed — yet the second run comes out faster. That's the trap Stefan Marr walks through using a fictitious payroll workload that behaves "reasonably deterministically." Frequency scaling, thermal budget, hybrid core types, JIT warming, and scheduler luck can all explain the same run-to-run variance. Modern systems are complex enough that the honest move is to hypothesize and verify, not assume you know what the clock says.