ARM-based Graviton2 consistently outperforms Intel x86-based processors in PostgreSQL test by Percona, and it’s 25% cheaper. If your workload is not x86-specific there’s no reason not to switch.
The rise of ARM-based processor is gaining momentum and it seems like Intel is seriously playing catch-up here.
With the second gen of Graviton2 instances announced, we decided to take a look at the price/performance from the standpoint of running PostgreSQL.
Source: PostgreSQL on ARM-based AWS EC2 Instances: Is It Any Good? – Percona Database Performance Blog