> ARM has done a fabulous job in marketing and executing itself as energy efficient. To be fair to ARM, they actually have produced energy efficient processors

> ARM has done a fabulous job in marketing and executing itself as energy efficient. To be fair to ARM, they actually have produced energy efficient processors. I don't know a lot about ARM processor internals, but I've seen some presentations from many years ago and they had clever tricks for saving power while running, such as only charging some transistors during part of a clock cycle. That doesn't mean the ISA is the reason for power efficiency, it means ARM designs have other tricks as well. Or at least, they used to.