I deal with low power microcontrollers. They keep using less and less power while running faster.
Old Z80 based board I first worked on drew 1A at 5V, so 5W. Put your hand on it, it's nice a warm. Current board I'm dicking with draws 8ma at 3V or 0.024W. 200 times less power. But it's 50 to 100 times faster.
