Cache quand utiliser APC ou Memcached ?

Bonjour,

Je voudrais cacher car je suis decu du cache fichier, encore trop lent.
Je me demandais quels est la difference ?

APC (http://pecl.php.net/package/APC)
 *
 * Cache::config('default', array(
 * 'engine' => 'Apc', //[required]
 * 'duration'=> 3600, //[optional]
 * 'probability'=> 100, //[optional]
 * 'prefix' => Inflector::slug(APP_DIR) . '_', //[optional] prefix every cache file with this string
 *  ));
 *
 * Memcache (http://www.danga.com/memcached/)
 *
 * Cache::config('default', array(
 * 'engine' => 'Memcache', //[required]
 * 'duration'=> 3600, //[optional]
 * 'probability'=> 100, //[optional]
 * 'prefix' => Inflector::slug(APP_DIR) . '_', //[optional] prefix every cache file with this string
 * 'servers' => array(
 * '127.0.0.1:11211' // localhost, default port 11211
 * ), //[optional]
 * 'persistent' => true, // [optional] set this to false for non-persistent connections
 * 'compress' => false, // [optional] compress data in Memcache (slower, but uses less memory)