> ARM is still ahead in perf/watt Citation needed. The Cortex M23 and M33 seem to have made a good step forward in efficiency compared to RISC-V, but those ar

> ARM is still ahead in perf/watt Citation needed. The Cortex M23 and M33 seem to have made a good step forward in efficiency compared to RISC-V, but those are microcontrollers. I haven't seen any indication of the Cortex A53/A55 being more efficient than the U74, or the A72 being more efficient than the C910. In fact the reverse. Maybe the A510 / A515 / A520 is better, but you can't buy an SBC with those. > the environmental impact for the existing box is already spent. That is certainly true.