Difficulty: Easy
Description
These databases use io1 Provisioned IOPS storage, but their IOPS fit within gp3 limits. gp3 delivers comparable performance for less.
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.