[Earw0rm]

The limits are engineering, not physics. Atoms need not be a barrier for a long time if you can go fully 3D, for example, but manufacturing challenges, power and heat get in the way long before that.

Then you can go ultra-wide in terms of cores, dispatchers and vectors (essentially building bigger and bigger chips), but an algorithm which can't exploit that will be little faster on today's chips than on a 4790K from ten years ago.