This is probably the first thing the author should try. Just a quick look at their own harness, it's sort of trying to guess what 'warmup' is required. The JIT

This is probably the first thing the author should try. Just a quick look at their own harness, it's sort of trying to guess what 'warmup' is required. The JIT kicks in at invocation counts, among other things, rather than time so the warmup on differently performing hardware or JVM implementations might be doing different things. JMH's purpose is to take that guesswork out of exactly that kind of microbenchmark.