Akka: multiple dispatcher vs multiple actor system

Question

I am wondering what would be the criteria to choose between having several actor systems in one application over having multiple dispatcher ?

What are the consequence of multiple actor system vs multiple dispatcher ? ( or advantage)

Answer 1

I can't see one reason to use multiple actor systems. They are resource-heavy.

Reasons for multiple dispatchers:
1) You need a different type of dispatcher (like a balancing dispatcher) for one part of the application.
2) A blocking operation is going on in one part of the code. While it is better not to block at all, if you really need to block, do so in a separate dispatcher.