bench_serialize.php

<?php

$array = array(
    1,
    2,
    'trois',
    4 => array('one', 'tow', 'three'),
    'cinq' => array('key' => array(
        'value' => 4
        ))
    );

$begin = microtime(true);

for ($i = 0; $i < 1000000; $i++) {
    $ser = serialize($array);
}

var_dump('serialize');
var_dump(microtime(true) - $begin); // double(2.5023109912872)
var_dump($ser); // string(141) "a:5:{i:0;i:1;i:1;i:2;i:2;s:5:"trois";i:4;a:3:{i:0;s:3:"one";i:1;s:3:"tow";i:2;s:5:"three";}s:4:"cinq";a:1:{s:3:"key";a:1:{s:5:"value";i:4;}}}"

$begin = microtime(true);

for ($i = 0; $i < 1000000; $i++) {
    $ser = json_encode($array);
}

var_dump('json_encode');
var_dump(microtime(true) - $begin); // double(1.8808162212372)
var_dump($ser); // string(78) "{"0":1,"1":2,"2":"trois","4":["one","tow","three"],"cinq":{"key":{"value":4}}}"