AWS Certified Solutions Architect - Professional (#455)

In Amazon RDS for PostgreSQL, you can provision up to 3TB storage and 30,000 IOPS per database instance. For a workload with 50% writes and 50% reads running on a cr1.8xlarge instance, you can realize over 25,000 IOPS for PostgreSQL. However, by provisioning more than this limit, you may be able to achieve:

higher latency and lower throughput.
lower latency and higher throughput.
higher throughput only.
higher latency only.