There are areas where you could make a typical current processor "up to 5%" faster in exchange for dumping various determinism features provided in hardware tha

There are areas where you could make a typical current processor "up to 5%" faster in exchange for dumping various determinism features provided in hardware that are conductive to software robustness in the same way as checked arithmetic. For example the Alpha had imprecise exceptions and weak memory ordering. The consensus seems to be against this kind of tradeoff.