you’d get more benefits by first moving to wp-multisite for the installs, the the opcode cache would be more efficient
It depends on what you are putting in the cache. Anthony is probably correct when it comes to object and DB caching. As for APC vs Memcache, I have found that most people are on the side of APC. It circumvents much of the PHP functionality and manages things itself, which is probably better.
As for Page and Minify caching, your best bet from my understanding is disk enhanced and disk caching.
It seems counter-intuitive, but it is supposed to make it so your webserver doesn’t have to load PHP, but can just server the files directly which is supposed to be much faster.
My opinion at least.
Using multisite in subdomain mode means that you will get better scale from PHP using APC for a smaller code base and then using APC as the backend cache for object caching and database caching for a single single codebase. Then using disk enhanced for page cache and disk mode for minify is probably your best bet.
Thread Starter
c
(@igneous)
I probably should have a long time ago, but I’ve had them running this way for years. There’s over 100,000 posts between the different sites, and I have applications and some other things accessing their databases to pull info. It was too complicated for me to even think about changing it