Here are my benchmark results:
      join:  2 wallclock secs ( 1.68 usr +  0.00 sys =  1.68 CPU)
      loop:  8 wallclock secs ( 7.60 usr +  0.02 sys =  7.62 CPU)
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#!/usr/bin/perl -w
use Benchmark;
 
 
 my @a1 = qw(3 99 4 33 43 98 83 64 3 99 4 33 43 98 83 64 99 4 33 43 98
+ 83 64);
 
 
 my @a2 = qw(3 99 4 33 43 98 83 64 3 99 4 33 43 98 83 64 99 4 33 43 98
+ 83 64);
 
 
sub join_eq {
   return join('',@a1) eq join('', @a2);
}
 
sub loop_eq {
  my $rc = 1;
  if ($#a1 != $#a2) { $rc = 0; }
  else {
    for (my $i=0; $i<=$#a1; $i++) {
      $rc = 0 if $a1[$i] ne $a2[$i];
    }
 }
 return $rc;
}
 
 
timethese(100000, {join => \&join_eq, loop => \&loop_eq});
[download]