gistfile1.php

<?php

$dir = '/tmp/speedtest'; #10k of files, ext4 FS
$steps = 20;

$times = array(0,0,0,0);

for ($round = 0; $round < $steps; $round++) {
	clearstatcache();

	$as = microtime(TRUE);
	$ite = new DirectoryIterator($dir);
	for ($ite->rewind(); $ite->valid(); $ite->next()) {
		$f = $ite->current();
	}
	$times[0] += microtime(TRUE) - $as;
	unset($ite, $f);

	clearstatcache();

	$bs = microtime(TRUE);
	for ($p = opendir($dir); ($f = readdir($p)) !== FALSE; ) {
	}
	closedir($p);
	$times[1] += microtime(TRUE) - $bs;
	unset($p, $f);

	clearstatcache();

	$cs = microtime(TRUE);
	$d = scandir($dir);
	for ($i = 0, $s = count($d); $i < $s; $i++) {
		$f = $d[$i];
	}
	$times[2] += microtime(TRUE) - $cs;
	unset($d, $i, $s, $f);

	clearstatcache();

	$ds = microtime(TRUE);
	$d = glob("$dir/*");
	for ($i = 0, $s = count($d); $i < $s; $i++) {
		$f = $d[$i];
	}
	$times[3] += microtime(TRUE) - $ds;
	unset($d, $i, $f, $s);
}

echo implode(', ', array_map(function ($t) use ($steps) { return $t / $steps; }, $times));