There is nothing inherently special about ARM that makes it use less power.
Apple simply invested a huge amount of resources and had the benefit of optimising the SOC specifically for the OS.
fmajid
Which is why Intel is an also-ran in mobile computing and IoT despite all the ressources it poured into it, I suppose?
The sheer amount of legacy in x86 is why those CPUs are so inefficient and require so much cooling. ARM would not have emerged if not for its superior efficiency.
Apple simply invested a huge amount of resources and had the benefit of optimising the SOC specifically for the OS.