Magento database collection speed tests

fetch.php

<?php

include_once('app/Mage.php');
Mage::app('default');

function makeWalker($collection, $modelName) {
    ///echo $collection->getSelect(). "\n";
    return array($collection->getSelect()->query(), $modelName);
}

function fetch($walker, $model = null) {
    $row = $walker[0]->fetch();
    if (!$row) return false;
    if (!$model) {
        $model = Mage::getModel($walker[1]);
    }
    $model->setData($row);
    return $model;
}

$start = memory_get_usage();
$time_start = microtime(true);

for ($i = 0; $i < 500; ++$i) {
    $collection = Mage::getModel('catalog/product')->setStoreId(1)->getCollection()
        ->addAttributeToSelect('*');

    $iterator = makeWalker($collection, 'catalog/product');
    $product = null;

    while ($product = fetch($iterator, $product)) {
    #    echo $product->getName() . "\n";
    #    echo $product->getPrice() . "\n";
    }
}

$end = memory_get_usage();
$diff = $end - $start;
echo "$start\n";
echo "$end\n";
echo "$diff\n";

$time_end = microtime(true);

$time_diff = $time_end - $time_start;
echo "$time_diff seconds\n";

foreach.php

<?php

include_once('app/Mage.php');
Mage::app('default');

$start = memory_get_usage();
$time_start = microtime(true);

for ($i = 0; $i < 500; ++$i) {
    $collection = Mage::getModel('catalog/product')->setStoreId(1)->getCollection()
        ->addAttributeToSelect('*');

    foreach ($collection as $product) {
#        echo $product->getName() . "\n";
#        echo $product->getPrice() . "\n";
    }
}

$end = memory_get_usage();
$diff = $end - $start;
echo "$start\n";
echo "$end\n";
echo "$diff\n";

$time_end = microtime(true);

$time_diff = $time_end - $time_start;
echo "$time_diff seconds\n";