Mine

<?php

$iter = 100;

function getmtime() {
  $a = explode (' ',microtime());
  return(double) $a[0] + $a[1];
}

for ($i = 0; $i < $iter; $i++) {
  $start = getmtime();
  $a = range(1, 1000);
  rsort($a);
  $loadtime += getmtime() - $start ;
  $intertime = getmtime() - $start ;
  echo $intertime . "<br>" ;
  $avgload = $loadtime / $iter;
}
echo "<p><b>" . $avgload . "</b>" ;