We run many more than 12 processes per server. That's how you can get around that. :) But that's frankly more of a Python architecture problem than Django. Django is compatible with coroutine libraries like gevent, just most of the ecosystem is not compatible, so that makes things difficult at the size we're at.

Realistically though, this isn't a problem for us and if things are done right, shouldn't be a problem for you either. Just use more processes and you'll be fine unless you're running out of RAM or something.