My limited understanding is that Apple A series chops benefited initially from expensive manual layout while many ARM chips of that time were using more machine

My limited understanding is that Apple A series chops benefited initially from expensive manual layout while many ARM chips of that time were using more machine driven layouts. Also Apple, as Apple does, city out a lot of legacy bits and pieces that Wintel are expected to support. So leaner more rigorously designed chips. Of course I could be off the mark here. As usual Anandtech has excellent deep dives into various SoCs: https://www.anandtech.com/show/11596/techinsights-confirms-apple-a10x-soc-10nm-tsmc https://www.anandtech.com/show/11596/techinsights-confirms-a... https://www.anandtech.com/show/9824/more-on-apples-a9x-soc https://www.anandtech.com/show/9824/more-on-apples-a9x-soc