Object Caching with Multidb 2.7.5

Object caching http://neosmart.net/dl.php?id=14 will work with multidb? I’m using multidb 2.7.5, have object caching enabled, but see no major enhancement. Also in wp-config.php you have to define( 'WP_CACHE', true ); in order for object caching to work, but multidb using db-config.php, will wp-config.php still matter and allow WP_CACHE to work?