Correct me if I'm wrong, but ARM is much less power hungry, and produces less heat. Both options that at scale means potential cost savings on resale.
It might not be enough to offset the other costs, but it could be enough to offer a less costly service. At the end of the day though, half of what you get with AWS is a ton of library support in many languages for using AWS services.
Performance and power are a complicated topic and Thunder-X2 might produce better numbers. 64-bit ARM for servers must be competitive with Xeons and POWER and can't compromise performance for power either.
