> As an aside, I'm not convinced by their motivating claim that current processors are power-inefficient. x64 / aarch64 / amdgpu seem to get a lot of maths done

> As an aside, I'm not convinced by their motivating claim that current processors are power-inefficient. x64 / aarch64 / amdgpu seem to get a lot of maths done per watt. Why does getting a lot of math done per watt preclude the possibility of a more efficient design? For example, aarch64 is generally more efficient than x64 from a perf/watt metric and GPUs are more efficient for a subset of problems. It’s not hard to believe that existing CPU architectures do not represent the Pareto frontier. For example, x86’s variable length encoding is known to be substandard from an efficiency perspective because the decode frontend can’t extract as much parallelism as a fixed length / aligned instruction set and in today’s machines that would be more impactful to fix than the memory bandwidth saved by a relatively inefficient compression scheme.