PHP function speed testing

O.K. So I've written my application and debugged it, and now I want to try and optimize the speed. I have written a little test script to test the time of each PHP function that I can use in a certain situation (ereg, eregi, strpos). Problem is, no matter what I do, the first function I test in the script is always the slowest, even if I reorder them so that strpos() is first instead of ereg(). Doesn't matter which one it is. Maybe I did something stupid and just can't see it? Below is the code: // define the stuff to use $GLOBALS['renderstart'] = 0; $key = "testkey"; $teststring = "test500"; $test = array( 'testkey' => array (

    'test50' =>
    array (
      'main' => 'admin.html',
    ),
    'test500' =>
    array (
      'main' => 'admin.html',
    ),
    'default' =>
    array (
      'main' => 'admin.html',
    ),

), ); // functions function start_timer() { $mtime = explode(" ", microtime()); $GLOBALS['renderstart'] = $mtime[1] + $mtime[0]; } function stop_timer() { $mtime = explode(" ", microtime()); $renderstop = $mtime[1] + $mtime[0]; $rendertime = ($renderstop - $GLOBALS['renderstart']); printf(" [ %f seconds ]<br>\n", $rendertime); } // test code $matchlen = 0; reset($test[$key]); start_timer(); foreach ($test[$key] as $ops => $vals) { if ((strlen($ops) > $matchlen) && ereg($ops, $teststring)) { $modops = $ops; $matchlen = strlen($modops); } } echo "ereg"; stop_timer(); $matchlen = 0; reset($test[$key]); start_timer(); foreach ($test[$key] as $ops => $vals) { if ((strlen($ops) > $matchlen) && eregi($ops, $teststring)) { $modops = $ops; $matchlen = strlen($modops); } } echo "eregi"; stop_timer(); $matchlen = 0; reset($test[$key]); start_timer(); foreach ($test[$key] as $ops => $vals) { if ((strlen($ops) > $matchlen) && ereg($ops, $teststring)) { $modops = $ops; $matchlen = strlen($modops); } } echo "strpos"; stop_timer(); Any ideas??? Thanks! -Shawn