<?php
define( '_JEXEC', 1 );
define('JPATH_BASE', dirname(__FILE__) );
define( 'DS', DIRECTORY_SEPARATOR );
require_once ( JPATH_BASE .DS.'includes'.DS.'defines.php' );
require_once ( JPATH_BASE .DS.'includes'.DS.'framework.php' );
$mainframe =& JFactory::getApplication('site');
$mainframe->initialise();


$query = 'SELECT * FROM #__content';
$limit = 50; // use 1 for $row

for ($i=0; $i<6; $i++) {
 test($query, $limit);
}

die;

function test($query, $limit) {
 $db =& JFactory::getDBO();
 
 $db->setQuery($query, 0, $limit);

 $total			= 0;
 $cycle_count	= 50;
 $step_count		= 50;
 
 $mem = memory_get_usage();
 
 for ($i=0; $i<$cycle_count; $i++) {
 $step 	= 0;
 for ($i2=0; $i2<$step_count; $i2++) {
 $time = microtime(true);
 
 $rows = $db->loadObjectList();
 //$rows = $db->loadAssocList();
 //$rows = $db->loadRowList();

 //$row = $db->loadObject();
 //$row = $db->loadAssoc();
 //$row = $db->loadRow();
 
 $step += microtime(true) - $time;
 }
 $total += $step;
 }
 
 echo '<br>-------------<br>';
 echo round($total/$cycle_count, 3);
 echo '<br>';
 echo 'Memory usage: ', sprintf('%0.2f', (memory_get_usage()-$mem)/1024 ).' kB';
}