Today, we are announcing the general availability of Amazon Neptune I/O-Optimized, a new configuration for Amazon Neptune Database that provides improved price performance and predictable pricing for customers with I/O-intensive applications. With Neptune I/O-Optimized, there are zero charges for read and write I/O operations—you only pay for your database instances and storage usage, making it easy to predict your database spend up front. Neptune I/O-Optimized offers up to 40% cost savings for I/O-intensive applications where I/O charges exceed 25% of the total Neptune database spend.
Source:: Amazon AWS