iops
The amount of Provisioned IOPS (input/output operations per second) to initially allocate for the DB instance. For information about valid IOPS values, see Amazon RDS DB instance storage in the Amazon RDS User Guide.
This setting doesn't apply to Amazon Aurora DB instances. Storage is managed by the DB cluster.
Constraints:
For RDS for Db2, MariaDB, MySQL, Oracle, and PostgreSQL - Must be a multiple between .5 and 50 of the storage amount for the DB instance.
For RDS for SQL Server - Must be a multiple between 1 and 50 of the storage amount for the DB instance.