PHP bench mark. Concatenation vs array collection + implode. What's faster?

Question

PHP

on different computers different results
who can say which is faster?
or who is not too lazy, test, tell me how you are
time php <file> > /dev/null

<?php
$out = '';

for ( $i = 0; $i < 1000000; $i++ ) {
    $out .= $i . '_' . $i;
}

echo $out;

?>

<?php
$out = [];

for ( $i = 0; $i < 1000000; $i++ ) {
    $out[] = sprintf('%s_%s', $i, $i);
}

echo implode('', $out);

?>

my ratio is
1) real: 0.4s
2) real: 1.4s

Answer 1

0.458655834198
1.3961231708527