use Benchmark;
$reps=500000;

$x.=("a".."z")[rand 26] for (1..256); 
Benchmark::cmpthese($reps, {
'sub256' => '$_=$x;s/e//g;',
'trn256' => '$_=$x;tr/e//d;',
});
print "-"x40,"\n";
$x="";
$x.=("a".."z")[rand 26] for (1..1024); 
Benchmark::cmpthese($reps, {
'sub1024' => '$_=$x;s/e//g;',
'trn1024' => '$_=$x;tr/e//d;',
});
print "-"x40,"\n";
$x="";
$x.=("a".."z")[rand 26] for (1..5120); 
Benchmark::cmpthese($reps, {
'sub5k' => '$_=$x;s/e//g;',
'trn5k' => '$_=$x;tr/e//d;',
});
print "-"x40,"\n";