Here’s two quick and easy steps you can take to increase your Wordpress sites speed:
Enable Wordpress’s Object Caching
Add define(‘ENABLE_CACHE’, true); to your wp-config.php to enable Wordpress’s built in object caching and Wordpress will begin caching all sorts of database queries resulting in an instantaneous performance boost.
Install WP-Cache 2
WP-Cache is a plugin which serializes and caches posts to disk for quick retrieval. It’s also smart enough to keep serialized data on the disk up to date so it won’t serve stale content.