Comparing the results of this Benchmark with my benchmark just below yields a startling discrepancy. My computers can barely manage 25 iterations a second, whereas Zaxo's seem to finish 15_000 iterations a second easily!

Actually, there's still a problem with the code above: it's measuring how long it takes to ``eval "perl -P -e '$foo'"'' (and something similar for $bar). But that's just string concatenation, with a useless eval thrown in (it fails; that's not legal Perl code!). You need actually to run the command line, say by s/eval/system/g;.