perl map vs for Benchmark

I want to test what’s the different between a map function and a for iteration with Perl is:

#!/usr/bin/perl
use strict;
use Benchmark qw(:all) ;
my @arr = (1..10);


print sub_map(@arr).$/;
print sub_for(@arr).$/;



cmpthese(-1, {
'sub_map'  => sub {sub_map(@arr)},
'sub_for'  => sub {sub_for(@arr)},
});

sub sub_map {
    return join",", map {$_ * 2} @_;
}
sub sub_for {
    for (@_){
        $_ = $_*2;
    }
    return(join",",@_);
}

Our Benchmark result:

2,4,6,8,10,12,14,16,18,20        
2,4,6,8,10,12,14,16,18,20        
            Rate sub_for sub_map 
sub_for 129153/s      --    -10% 
sub_map 142717/s     11%      --

map is about 11% faster than a simple for loop.