That'll definitely give you a speed boost, as the interpreter doesn't have to get involved (if configured right). However, this article is talking about IO clogging apache workers. The issue is that the worker must do two jobs: generate the page (using mod_php) then send it to the client. Using nginx in front of apache means that nginx handles the IO to the client (which it is extremely good at), leaving the apache workers to handle nothing but generating pages, hence getting overall higher requests/sec from the same machine.