Something I often hear is that the modern CPU has bunch of sort of “poly fills” to merge the programming paradigms of past with new tech. Microcode perhaps mostly. Like that C programming, which mostly forms basis for other absractions no longer captures how a cpu works, and the cpu tries to optimize C type abstractions for modern post 80/90s innovations.

What would a new paradigm for CPU and GPUs look like? Is there some aspect of the legacy system that is not ideal but clearly economically impossible to change. Does the poly fill type design of cpu microcode have drawbacks?

One analogy is planes. Plane design has remained pretty unchanged since 1960s because of regulations, very different design = pay to retrain pilots. Of course planes have still drastically improved across board, but but they are still controrting themselves to adhere to the paradigm of the pilots for economic reasons. Without this, a new plane design might be quite different. (This is part of the Boeing crisis- the software was designed to “polyfill” the change in flight beahvior caused by the contorting themselves to get a better engine on similiar plane frame)