I store sessions in memcache and have noticed that quite a lot of memory is being used for memcache now. Check the following screenshots: Does this seem normal? 8 and 9 have over 20k items and the age is quite long. If you click on them it all shows session info. Not really sure what most of this means so if anyone can shed some light that would be great. Here is my setting in config.php Code: $config['cache']['enabled'] = true; $config['cache']['frontend'] = 'Core'; $config['cache']['frontendOptions'] = array('caching' => true, 'automatic_serialization' => true, 'cache_id_prefix' => 'aspies_' ); $config['cache']['cacheSessions'] = true; $config['cache']['backend'] = 'Memcached'; $config['cache']['backendOptions'] = array( 'servers' =>array( array( 'host' => '127.0.0.1', // your memcached server ip /address 'port' => 11211 // memcached port ) ), 'compression' => false ); I use this same setup, minus the prefix for each site on the server.