With caching now in 1.8 should memcached be added?

Question

What more would memcaching add?

Answer 1

memcached needs to be installed on your server first

Answer 2

You don’t need to use memcached. The basic filesystem cache works fine for most purposes.

Memcached is an in-memory cache and should be faster, though I haven’t done much performance testing on a live system.

Comments

I am using memcached on a very large site. What would you say are the best metrics to look at as far as performance and what is the best way to measure them? Also, can you clarify, the specified number of days, is this days from last new activity (comment/answer) or days from when the question was asked? How long does cache time need to be to really make a significant difference in performance? My site has 70,000+ questions many old questions get quite a bit, (sometimes hundreds of visits per day)  of activity and sometimes new answers are posted even a few years after the question was asked. Just trying to find the best settings for me.