Check out a high resolution side-by-side of the Cloud Assist demo we showed off at Build 2014 during Steve Guggenheimer's keynote. One side is a single computer doing all of the physics calculations real time by itself, the other is a computer taking advantage of remote destruction servers doing those calculations.

This is real time physics and lighting calculations and not scripted, and ends up being tens of thousands of individual chunks being thrown through the air and interacting with each other.