While power draw can't be measured in an AWS instance, there's no particular reason to suspect there's anything all that interesting here. Other ARM 64-80 core chips have the "normal" ~200W TDPs you'd expect to find in server CPUs of this type, and there's been very little difference in general power efficiency between ARM & x86 for many years now. ISA doesn't matter much here, it's more about the target design & performance the chip is trying to hit.

We have added both a cost and power consumption comparison to the blog post (including AMD EPYC as well), here is a snippet:

| Instance type | m6g.16xlarge | c5.18xlarge | c5.24xlarge | c5a.24xlarge |

| Architecture | Graviton2 | Skylake | Cascade lake | AMD EPYC |

| CPU(s) | 64 | 72 | 96 | 96 |

| RAM (GiB) | 256 | 144 | 192 | 192 |

| $/hour | $2.464 | $3.06 | $4.08 | $3.696 |

| Power usage (W) | ~115 | ~240 | ~240 | ~280 |

On the assumption performance equals this particular workload, then Graviton ( Or specifically Graviton 2 ) should, with an extremely high degree of certainty have an upper hand.

To answer your question in its general form, you have to take into account what types of "performance" you are interested in, and what Node these CPU are manufacturers in, Not to mention there are different form of Graviton and Intel ( x86 )

There's no way to know the power consumption of stuff in AWS.

However, how much they charge for it gives a general idea, since they are paying for the power.

That could or could not be correct. We don't know their bill of materials. Probably some people can estimate it better for Intel. I understand the ARM stuff is AWS proprietary, so I would be surprised is any figures are public. Besides the costs are unkown the margins could be very different. AWS might be willing to pay a high investment to get more independent of Intel in the long term.

I worked at a big corporation in the mobile space before. They were willing to pay a high investment to get more independent of their single ARM SoC supplier. (It failed because Intel could not deliver in the end.)