There are a couple distinct issues here - M1 is both wider than recent x86 but also more orthogonal. I'm not sure that decode is the bottleneck for all code -

There are a couple distinct issues here - M1 is both wider than recent x86 but also more orthogonal. I'm not sure that decode is the bottleneck for all code - a lot of code could be played out of a pre-decoded uop cache or the LSD. People always return to decode as an explanation as it's an attractive RISC vs CISC morality tale. I also don't know how much of the decode unit is devoted to legacy support and MSROM, which doesn't necessarily have to scale the same way as the simple decoders.