The place where you miss the point is that you still have only one CPU. There is no magic that will allow you to run things concurrently on single CPU in this world. In general if you process linear data (like files) then there is no point in doing that in more processes (system processes) than there is cores in your CPU, in Erlang terms - it is not feasible to process streams of data in more processes than you have schedulers enabled in your system (and it makes no sense to run more schedulers in your system than you have physical cores).
So there is no magic in this world that will speed up that files processing by running processing in multiple threads on the single core.
