$ 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%     --

##</code><code>##

Benchmark: running substr, vec for at least 60 CPU seconds...
    substr: 62 wallclock secs (61.69 usr +  0.05 sys = 61.74 CPU) @  0.44/s (n=27)
       vec: 61 wallclock secs (60.81 usr +  0.05 sys = 60.86 CPU) @  0.39/s (n=24)
       s/iter    vec substr
vec      2.54     --   -10%
substr   2.29    11%     --