I think that it's actually not an unreasonable question and the prior answer was a little short! For example ARM has different ISAs depending on the applicatio

I think that it's actually not an unreasonable question and the prior answer was a little short! For example ARM has different ISAs depending on the application: A for more complex Application processors, R for Realtime and M for Microcontroller. The ISA for M is less complex, less complex to implement and likely to use less power than A (or than a full x86 implementation). Not an expert but from what I've seen Super-H seems like a good candidate for a low power applications.