I don't use Benchmark that much (not really an issue for the code I write) so I'm not familar with the finer aspects of the module.

Personally if I would look to the table produced at the end of the output over the wallclock secs

As jasonk suggested, running through more iterations may give a clearer difference in results

!unlike

"The price if ignorance, which is of course that you must learn from those who know." Socrates (paraphrased)