D. S. Ljungmark:
You have to start another Tor instance to use a little more your CPU
(1 other core) and so to drain additionnal 150-300Mbps.
Scaling up on more hardware is always an option, but I really want to push the limit of the exit node, as the others won't be exits (Local network design, really) , and exit traffic is always more interesting.
Aeris (and others) were not referring to run more instances on other hardware but to run more instances on the same hardware/machine. (multiple tor instances on one machine has become easy to setup nowadays)