Which one is best to use? And which one do you use?
I tried W3 and it quadrupled the load on our VPS. Supercache never did. No idea if that is common, but DH recommends W3 over Supercache.
Your mileage may vary…
I think i’ll go with Supercache then.
I’ve only had terrible experiences with W3 Total Cache, for all of my 4 WP sites: it went from taking a site down completely to returning 404 errors on all pages except for the homepage, as some rewriting rules went berserk. Uninstalling it is also slightly troublesome, as it tends to leave a stuffy .htaccess that you will need to clean yourself. As many others have pointed out, W3 Total Cache appears to be overkill for a normal WP installation.
WP Super Cache, on the other hand, works like a charm and is much easier to work with, even for someone who isn’t very knowledgeable about how caching works. Word of advice: although I have successfully used mod_rewrite caching with WP Super Cache and it’s definitely the fastest, I noticed it did incur quite some load. I then changed it to php caching and the server load went down to half. Depending what your priorities are, you might want to opt for php caching - it’s only marginally slower than mod_rewrite but more efficient load-wise.
This is a very interesting observation. mod_rewrite doubling the CPU demand seems incredible. Do you also have FastCGI enabled in order to further lower the potential load when using PHP caching?
Great post by the way, and thanks for sharing your experience. It outlines very well that experimenting with the different caching methods available is worthwhile and that alternative mechanisms can lead to better server performance for any given website.
I have no clue why it would behave that way, but I tested it 3 times in 3 different days, alternating mod_rewrite and php and got the same results. Here’s a visual of what I recorded, you can see where the cache is cleared and rebuilt: http://i.imgur.com/yBHGQB8.png .
And yes, the server is set to 5.3 FastCGI, never changed the php mode.