parmutate.php

<?php

function permutate($array) {

    $current = array_shift($array);
    $result = array();

    if ($array) {
        foreach (permutate($array) as $permutation) {
            foreach ($current as $value) {
                $result[] = array_merge(array($value), $permutation);
            }
        }
    } else {
        foreach ($current as $value) {
            $result[] = array($value);
        }
    }

    return $result;
}

$input = array(
    array('asus', 'gigabyte'),
    array('onboard', 'radeon', 'nvidia'),
    array('kingston', 'mushkin', 'corsair'),
    array('samsung', 'western digital', 'seagate')
);

$result = permutate($input);
echo json_encode($result, JSON_PRETTY_PRINT);