I was hoping maybe some one had an article or could give me some feedback on the following settings.php configuration that I'm currently using to push Drupal 7 cache bins to APC user cache and the file system via the File Cache module. Best performance numbers I got was APC for everything but that obviously has some issues with fragmentation of the smaller cached values. Some context of what I'm also using for performance
-- Display Cache https://drupal.org/project/display_cache
-- Entity cache https://drupal.org/project/entitycache
-- This system is a multi-multi site via DSLM https://drupal.org/project/dslm
-- Users of the system are almost 100% authenticated, primarily for viewing content though they will be submitting content in the future.
-- Server has 4 gigs of ram, 256 M currently dedicated to APC caching.
-- primed opcode cache sits at about 100 M
Currently most sites pull page loads (via devel stats) of between .15 and .25 seconds with minimal traffic (15-20 concurrent people on the box), we're just easing into the semester so I'll have a better idea of what that looks like when there's greater traffic. We have a theoretical max right now of around 1000 though the most we'll probably get at any one time is more like 50-80.
Any feedback about bin optimization would be appreciated.