Upgrade from 16 Dbs to 256 Dbs?

Is upgrading from 16 to 256 as easy as adding the other 240 DBs to the db-config.php file? My site recently went from 10 blogs to 76(in less than 24hrs) and Its starting to lag a little more that I would like. I assume that adding more DBs would help with this. Am i correct?

Also, does anyone know any good ways to speed up the site? Would having the DBs and Files on different servers work? I do not have physical access to my servers, but I do have ssh access(but no experience with ssh).