Microsoft SQL Server on AWS RDS: How to Significantly Reduce Licensing and Infrastructure Costs
Anyone running Microsoft SQL Server on Amazon RDS knows the financial challenge: the instance class directly impacts overall running costs. Since Microsoft SQL Server is licensed per vCPU, licensing often accounts for more than 90% of the annual cost for large Enterprise databases.
With the new AMD-based RDS instance classes M8a (General Purpose) and R8a (Memory Optimized), powered by 5th-generation AMD EPYC™ “Turin” processors, the economics of running SQL Server on AWS are fundamentally changing.
Why Choosing the x86 Architecture Matters
On AWS, the Graviton architecture (Arm) is often the go-to choice for cost optimization. However, this option is not available for Microsoft SQL Server: SQL Server is x86-based and is not supported on Amazon RDS for Graviton.
The key to reducing costs therefore lies in choosing the right x86 processor. This is where AMD EPYC™ delivers a clear advantage over traditional Intel-based instances (M8i / R8i).
Limited-Time Offer: Request Your Free 1-Workload Assessment Now
The 4 Key Benefits of AMD EPYC™ for SQL Server on RDS
- Higher Throughput per Core: Each vCPU on M8a and R8a instances corresponds to a full physical core. The memory-optimized R8a delivers up to 63% higher OLTP throughput than comparable Intel R8i instances. M8a delivers up to 35% higher OLTP and up to 47% higher analytics (OLAP) performance.
- Drastic Licensing Cost Savings: Higher performance per core allows you to handle the same workload with significantly fewer licensed cores. Including the Microsoft SQL Server license, transaction costs on R8a can be reduced by up to 36%.
- Infrastructure Efficiency and Sustainability: Even excluding SQL Server licensing, infrastructure costs per transaction can be reduced by up to 29%. In addition, M8a instances consume around 320 watts—roughly half the power of comparable Intel instances (~600 watts).
- Maximum Flexibility with RDS Optimize CPU: Reduce the number of active vCPUs with fine-grained control while retaining the instance’s full RAM capacity. This allows you to pay only for the SQL Server licenses your workload actually requires.
Performance & Savings Potential at a Glance
| CLAIM | COMPARISON | RESULT | |
|---|---|---|---|
|
SQL Server OLTP throughput R
|
|
Up to 63% higher (1.63x at xl; 1.35x at 4xl) |
|
|
Cost per transaction, with SQL license |
|
Up to 36% lower9xx5C-087
|
|
|
Cost per transaction, infrastructure only
(licensing excluded)
|
R8a vs. R8i |
Up to 29% lower |
|
|
SQL Server, general purpose
|
|
Up to ~35% OLTP; ~47% OLAP at 4xl |
|
|
Power draw
|
|
~320 W vs. ~600 W |
Seamless Drop-In Migration Without Application Changes
Because M8a and R8a are fully x86-compatible, moving to AMD-based instances requires no application changes. Migrations can be performed as usual, without downtime, using native methods such as Backup/Restore, AWS Database Migration Service (DMS), or Log Shipping. All familiar RDS features—including automated backups, Multi-AZ deployments, and patch management—remain fully available.
PCG’s Free Workload Assessment
Would you like to find out how much you could save on your databases? As part of the SQL Server on RDS Acceleration Program, we offer a free, no-obligation assessment.
- Setup Phase: Joint selection of a representative SQL Server database.
- Analysis Phase: Measurement of current performance and TCO modeling on RDS M8a/R8a.
- Result: Presentation of a validated business case, including a concrete savings analysis.
Looking to reduce licensing and infrastructure costs across your SQL Server environment? Get in touch with our AWS experts and schedule a no-obligation consultation.
Here for your journey.