How is being faster equating to more intelligent . Speed can achieved in a lot of ways for lot of tasks, a simple lookup table can fasten most algorithms but that doesn’t make them “smarter”.
1. How long can the model work and still make progress
2. How fast does it get to interesting places.
We see N -> N+1 models getting better at (1), but it does take work to measure because you need to find tasks that were impossible for N and possible for N+1.
However (2) is very easy to measure, because you can keep using the evaluations you used for the previous generation of models and see if the new system gets there more easily. This is useful by itself (cost savings) and also in practice generally translates into being able to solve harder problems than before, as you'd expect.