Input on caching methods?

If you're trying to cache for performance, usually DB calls are the slowest part of any application, so caching the data will allow you to see the biggest improvement.

So I'd recommend caching the data. You can use file based caching (slowest), or some other form of caching like Memcached or Redis (Very fast). CI has drivers for both of them and all you'll have to do is run a memcached or redis server and connect them accordingly.

Are you experiencing a lot of page hits or serious performance issues? If you are only getting a couple hundred page hits an hour and your sql queries are optimized, there usually isn't much need at all for caching.

Codeigniter is simply one of the tools you need to learn to be a successful developer. Always add more tools to your coding arsenal!