my $f = 50;
use Benchmark;
use strict;
use List::Util qw(first);
my @x = (0..$ARGV[0]||1000);
Benchmark::timethese(-2, {
Grep => sub{my $y  = grep {$_ == $f} @x},
Util => sub {my $y = first {$_ == $f} @x} });
' 100
Benchmark: 
running
 Grep, Util
 for at least 2 CPU seconds
...

      Grep:  2 wallclock secs ( 2.00 usr +  0.00 sys =  2.00 CPU) @ 46457.50/s (n=92915)

      Util:  2 wallclock secs ( 2.00 usr +  0.14 sys =  2.14 CPU) @ 76733.18/s (n=164209)