My reference to AI was due to the fact that real games use lots physics and AI, now my understanding of geometry instancing is that's it's meant to remove a lot of the cpu overhead of rendering the same object several times. This reduction in cpu overhead means that games can employ more objects in realtime and it won't impact the cpu time left for other necessary AI and physics tasks. This demo like democoder pointed out, looks heavily precomputed in path and behaviour, if it's using 100% cpu just do a very dumb display of lots of characters on screen, forget seeing that many characters in any real game for a long while.