gistfile1.aw

<?php
ini_set('memory_limit', '8192M');
$iterations = 10000000;
$data = array();

for ($i = 0; $i < $iterations; $i++) {
    $data['iteration' . $i] = array();
}

echo sprintf("Memory used: %0.2f MB\n", memory_get_peak_usage(true) / floatval(1024 * 1024));

// prints "Memory used: 3181.50 MB"