ARM doesn't use micro-ops in the same way as x86 does at all. And that's not the only difference, e.g. x86 has TSO.

I'm not saying the skill of the design team makes zero difference, but it's ludicrous to say that the ISA makes no difference at all.

The claims about the M1 Ultra appear to be marketing nonsense:

https://www.reddit.com/r/MachineLearning/comments/tbj4lf/d_a...