Is it duplicated if I cache an object that uses data from postmeta?

If the generation of the graphic presentation requires a lot of CPU time or memory, then yes, you could cache your graphic presentation (HTML I guess, right?). Perhaps in the database/memory, as a transient. Caching post meta data (that you use to generate the graphic) is not necessary, because WP already handles this. If you … Read more

Files cached as CSS or PHP?

A great deal of this will depend on your server configuration, but: Will WP Super Cache cache the css.php output? Extremely unlikely. If your file simply generates CSS from a few variables, then no. If however it bootstraps and loads WordPress, then it ‘might’ cache some things, but I doubt it will work as you … Read more

WebHostingBuzz cache statement

The point of caching is to increase performance, not specifically to reduce server load, but there is pretty obviously a relationship– perhaps not exactly the one(s) you expect. This is by no means a canonical answer but here are several things I can think of: Some kinds of caching increases memory usage. Caching that uses … Read more