Alternative caching engines
Your server might offer a dedicated caching engine such as APC or Memcached. You can leverage it with one line of PHP.
concrete5 employs Zend Frameworks File cache out-the-box, however you're not constrained to using the Zend_cache library alone. Indeed, your web server may well have a dedicated caching engine such as APC or Memcached already installed, which may offer better performance, and with a single line of code you can make concrete5 use that engine instead.
APC and Memcached are just two caching engines, there are others, but if you do have either of these caching engines installed and want to use it, simply add the appropriate line of PHP to your concrete5 installation's /config/site.php file:
It's so easy to set up, that I bet you'll forget to do it 90% of the time. I do!