Well, we can't answer that question at this point. We do know that the system is more powerful than a human, so the question becomes "How much hardware can we take away and still be better than the best". That sets the hardware floor we have to reach.

The current answer is, still a long way off. With massive forecasts in GPU power over the next few years it may be reasonable for people to have desktops in their home with this kind of power possibly within a decade. I won't even give a timeline for phones because of the power requirements.