Amazon Relational Database Service (Amazon RDS) Customfor Oracle now supports R5b and x2iedn instances. These instances are designed to deliver high EBS-optimized throughput and IOPS to enhance performance of Oracle database workloads that require high IO and that process large data sets in memory. Amazon RDS Custom for Oracle customers, with right-sizing, can migrate their database instances to smaller-sized R5b or x2iedn instances and still meet their workload throughput, IOPS, and memory requirements, saving on compute and database licensing costs.
Source:: Amazon AWS