Ask HN: Strange execution times of Javascript and PHP

just for fun I executed this in javascript:

  function test()
  {
   var r=1;
   for (var i=0;i<10000000;i++)
   {
    r*=1.0000001;
   }
   return r;
  }
  var start = (new Date).getTime();
  test();
  diff = (new Date).getTime() - start;

And this in PHP:

  function test()
  {
   $r=1;
   for ($i=0;$i<10000000;$i++)
   {
    $r*=1.0000001;
   }
   return $r;
  }
  $start = microtime(true)*1000;
  $r=test();
  echo "$r\n";
  $stop = microtime(true)*1000;
  echo $stop-$start."\n";

Any ideas to explain these differences?