Amazon Elastic Compute Cloud (EC2) I4g storage-optimized instances powered by AWS Graviton2 processors are now generally available. I4g instances deliver the best compute price performance for a storage-optimized instance versus comparable x86-based storage optimized instances, and the best storage performance per TB for a Graviton-based storage instance. Based on AWS Nitro SSDs that are custom built by AWS and reduce both latency and latency variability, I4g instances are optimized for workloads that perform a high mix of random read/write and require very low I/O latency, such as transactional databases (Amazon DynamoDB, MySQL, and PostgreSQL) and real-time analytics such as Apache Spark.
Source:: Amazon AWS