Difficulty: Medium
Description
These databases use an older instance generation. Newer classes, including Graviton, cost less and perform better.
Selection Criteria
The RDS instance uses one of these older generation families:
db.t2,db.t3,db.m3,db.m4,db.m5,db.m6i,db.c3,db.c4,db.c5,db.c6i,db.r3,db.r4,db.r5,db.r6iThe instance has been running for at least 30 days
A newer generation equivalent instance type is available in the instance's region
⚠️ Warning — SQL Server: Graviton is not supported for SQL Server RDS instances. Only Intel/AMD equivalent upgrades apply.
Expected Saving
Savings depend on the target generation and architecture:
Upgrade path | Example | Typical savings |
Same arch, newer gen (e.g. db.m5 → db.m6i) | db.m5.large $0.190/hr → db.m6i.large $0.184/hr | ~5–10% |
AMD equivalent (e.g. db.m5 → db.m6a) | db.m5.large $0.190/hr → db.m6a.large $0.173/hr | ~9% |
Graviton (e.g. db.m5 → db.m7g) | db.m5.large $0.190/hr → db.m7g.large $0.173/hr | ~10–20% |
Example: db.m5.large → db.m7g.large in us-east-1:
Before: $0.190/hr × 730 hrs = $138.70/month
After: $0.173/hr × 730 hrs = $126.29/month
Savings: ~$12.41/month (~9%)
Operational Impact
Downtime: Required — changing the RDS instance type requires a DB modification with a maintenance window. Can be applied immediately or deferred to the next scheduled maintenance window.
Breaking changes: Generally none for same-architecture upgrades (Intel → Intel or Intel → AMD). For Graviton, verify DB engine and version compatibility before proceeding.
⚠️ Warning — Multi-AZ deployments: A failover/promotion will occur automatically for Multi-AZ instances — expect a brief interruption (~30–60 seconds).
⚠️ Warning — SQL Server: Graviton is not available for SQL Server. Ensure the recommended target is an Intel/AMD type.
Recovery: Revert to the previous instance type via another modification — no data is affected.