My server uses eAccelerator and Zend Optimizer... do I still need to edit my config.php? Or can I just use this?
eAccelerator and Zend Optimiser are OpCode caches (they cache the compiled versions of the PHP code, saving lots of processing time) but they are not user data caches. For that you need APC, Memcached or file caching (or any of the other Zend_Cache_Backend options)
50+ posts on file caching split off to here: http://xenforo.com/community/threads/how-do-i-enable-file-caching.19713/
Nice little addition, I actually write it like that in other forum software for efficiency, automating it makes it a lot easier.