[rsynnott]

> but if they got within say 15% on performance and battery life would that be good enough?

I mean, depends what you mean by 'good enough'. It would, obviously, be good for AMD; I don't see that it would make it competitive in perf per watt terms, though.

> e.g. they seem to have speeded up handling of reference counting through architectural changes

They have, but that wouldn't be relevant to (most) synthetic benchmarks, I wouldn't have thought. SpecInt2017 won't be doing much if any reference counting, for instance :) The M1's advantage in ObjC and Swift should be expected to be even greater than its advantage in 'normal' (ie C) code, but beyond refcounting microbenchmarks I don't think there are many tools to demonstrate that (and the vast bulk of performance-sensitive code running on MacOS is C/C++ anyway).