$ perl -w 666965.pl Benchmark: running substr, vec for at least 60 CPU seconds... substr: 67 wallclock secs (60.69 usr + 0.03 sys = 60.72 CPU) @ 0.58/s (n=35) vec: 66 wallclock secs (61.33 usr + 0.04 sys = 61.37 CPU) @ 0.54/s (n=33) s/iter vec substr vec 1.86 -- -7% substr 1.73 7% --