You can now launch R5 instance types when using Amazon Relational Database Service (RDS) for MySQL and Amazon RDS for MariaDB. Amazon EC2 R5 instances are the next generation of Amazon EC2 memory optimized instances. R5 instances are based on the Amazon EC2 Nitro System, a combination of dedicated hardware and lightweight hypervisor which delivers practically all of the compute and memory resources of the host hardware to your database instance.