As you say, that model is bad. Specifically, it assumes that the change from speed 1 to speed 2, and the change from speed 2 to speed 4, take the same amount o

As you say, that model is bad. Specifically, it assumes that the change from speed 1 to speed 2, and the change from speed 2 to speed 4, take the same amount of compute time to design. That is almost certainly false; if it were not, humans would have quickly gone faster than Moore's Law.