gistfile1.txt

<?php
$stringa = 'a';

for ($i = 0; $i < 100000; $i++) {
    $string = str_repeat('a', $i*10000);
    echo $i*10000 . ' ';
    $stop = [];
    for ($j=0; $j<50; $j++) {
        $start = microtime(true);
        $result = (strlen($stringa) !== strlen($string));
        $stop[] = microtime(true) - $start;
        usleep(10);
    }
    $stop = array_sum($stop) / count($stop);
    echo number_format($stop, 10) . "\n";
}