Difficulty: Easy
Description
We identified several RDS instances in your account using io1 storage. This storage type is designed for high-performance workloads requiring consistent IOPS. However, for instances with IOPS requirements below 16,000, migrating to gp3 delivers equivalent or better performance at a significantly lower cost.
Selection Criteria
The RDS instance uses io1 storage type.
The RDS instance has been in constant use for the last 7 days.
The provisioned IOPS is less than 16,000.
Expected Saving
io1 costs $0.119/GB/month + $0.119/IOPS/month for every provisioned IOPS. gp3 costs $0.115/GB/month with 3,000 IOPS included at no extra charge.
The savings are substantial: a 100 GB io1 instance with 3,000 IOPS costs ~$369/month vs ~$12/month on gp3 — a reduction of over 95%.
Operational Impact
Storage type changes are applied online — no instance restart or downtime required. The modification runs in the background.
⚠️ Warning — IOPS ceiling: gp3 supports up to 64,000 IOPS max, while io1 can reach 256,000 IOPS. This recommendation only applies to instances with provisioned IOPS < 16,000, which is safely within gp3 limits.
⚠️ Warning — Performance validation: Monitor CloudWatch
ReadIOPSandWriteIOPSafter migration to confirm gp3 meets the workload's actual requirements.⚠️ Warning — 6-hour cooldown: After the modification completes, a 6-hour cooldown applies before another storage change can be initiated on the same instance.