I never thought about it before, but you're right. In the old days (ie. before chat-bots) while writing code, I was usually in an alpha state. This makes so much sense.
Does the M series have a flat memory model? If so, I believe that may be the difference. I'm pretty sure the entire x86 family still pages RAM access which (at least) quadruples activity on the various busses and thus generates far more heat and uses more energy.