MS-SQL Server EC2 standalone vs AWS RDS managed - Cost and Components Comparison

1. MS-SQL Server EC2 Standalone

Running Microsoft SQL Server on Amazon EC2 instances offers flexibility and control, but it also involves a range of cost components that must be carefully considered to align with business needs. While this approach may appear cost-effective upfront, especially for development or non-critical workloads, it demands manual management of licensing, backups, failover, monitoring, and patching.

Cost Components:

1. SQL Server Licensing
2. EC2 Instance Pricing
3. Elastic Block Store (EBS) Storage
4. Data Transfer Charges

Licensing Costs:

Licensing costs vary based on the edition and licensing model selected:

• Pay-as-you-go (License Included) pricing:

  a) Standard Edition: $73 per core per month (~$0.10/hr)

  b) Enterprise Edition: $274 per core per month (~$0.375/hr)

• Subscription-based licensing:

  a) Standard Edition: $1,418 per 2 cores per year

  b) Enterprise Edition: $5,434 per 2 cores per year

Licensing costs must be multiplied by the number of cores used in your EC2 instance.

Licensing Notes:

• A single SQL Server license includes one passive standby in the same region. This standby is non-operational and intended for high availability (HA) only—no read or write workloads can be executed on it.
• For cross-region disaster recovery (DR), only Enterprise Edition supports readable replicas. Additionally, a separate license must be procured for the DR server.

For complete and up-to-date Microsoft SQL Server licensing details, refer to the official pricing guide:
Microsoft SQL Server 2022 Pricing

Other Cost References:

• EBS Pricing: Amazon EBS Volume Pricing
• EC2 On-Demand Pricing: Amazon EC2 Pricing
• Data Transfer Pricing: AWS Data Transfer Pricing

Cost Example (Region: US East – N. Virginia)

Let’s consider a deployment using an r5.xlarge instance (4 vCPUs = 2 physical cores):

• EC2 Instance Cost (Windows Base AMI):

  $0.436/hour = $3,817.44/year

  With passive standby: $7,634.88/year

• EBS gp3 (200 GB):

  $0.08/GB/month = $192/year

• Data Transfer:

  100 GB between AZs (same region): ~$1

  100 GB to another region: ~$2

• SQL Server Enterprise License:

  $5,434/year (for 2 cores)

Total Estimated Annual Cost (Without DR):

• EC2 (Primary + Standby): $7,634.88
• SQL Enterprise License: $5,434
• EBS Storage: $192
• Total: ~$13,260/year

Total Estimated Annual Cost (With DR in Another Region):

• Add a second SQL Server license: $5,434
• Add another EC2 instance + EBS: ~$6,822
• Total: ~$22,516/year

2. RDS managed MS-SQL

Amazon RDS for SQL Server is a fully managed service provided by AWS, designed to reduce operational overhead by handling routine database tasks such as provisioning, patching, backup, monitoring, and failover. It is particularly well-suited for production environments that require high availability, compliance, and scalability, with minimal manual intervention.

You can learn more about Amazon RDS vs Amazon Aurora here.  This helps you gain further clarity on the concept we’re discussing. 
In this model, AWS includes licensing costs for both Windows Server and Microsoft SQL Server under the License Included pricing model, which simplifies procurement and compliance management.

Key Cost Components:

1. AWS RDS Instance Pricing (includes SQL Server Enterprise license)
2. Elastic Block Storage (e.g., gp3 or io1 volumes)
3. Optional Data Transfer Charges
4. Optional Cross-Region Disaster Recovery (DR)

Example Configuration (Region: US East – N. Virginia)

• Instance Type: db.r5.xlarge
• Edition: Microsoft SQL Server 2022 Enterprise
• Deployment Type: Multi-AZ (for high availability)
• Storage: 200 GB gp3
• Backup Retention: Default (7 days)

Estimated Costs:

• Monthly Cost: $2,675
• Annual Cost:
• $2,675 × 12 = $32,100/year

• With DR in Another Region:

  A second RDS instance in a different region would incur a similar cost (license + compute + storage), plus cross-region data transfer.
  Estimated annual cost including DR: ~$54,300/year

For more detailed pricing of RDS MS-SQl Server, please refer to this resource.

For r5.xlarge instance type - 4vcpu and 32gb memory

Although Amazon RDS for SQL Server Enterprise (Multi-AZ) may appear more expensive than a standalone AWS EC2 deployment, it delivers significant long-term value by reducing operational complexity, improving reliability, and providing full AWS support—making it ideal for production-grade and high-availability workloads.

Primary Advantage: Full AWS Operational Support

With Amazon RDS, AWS manages the entire database environment, including infrastructure, patching, backups, and monitoring. In the event of performance issues or failures, AWS Support can investigate and resolve them directly. In contrast, Amazon EC2-based deployments leave all responsibilities—database configuration, patching, backup, and recovery—on the customer, with AWS support limited to the EC2 layer only.

Key Benefits of RDS (Multi-AZ) vs. EC2 Standalone SQL Server

• Managed High Availability:
  AWS RDS provisions a synchronous standby in another AZ with automatic failover. On Amazon EC2, this requires a complex manual setup of clustering or Always On.
• Automated Backups & Point-in-Time Recovery:
  Amazon RDS handles backups and PITR natively. On Amazon EC2, this must be scripted and managed manually.
• Automated Patching & Maintenance:
  AWS RDS applies patches during maintenance windows. AWS EC2 requires manual patching, increasing risk.
• Integrated Monitoring:
  RDS integrates with CloudWatch for real-time insights. EC2 requires a custom monitoring setup.
• Simplified Licensing:
  AWS RDS includes SQL Server and Windows licenses. EC2 requires BYOL or License Mobility management.
• Security & Compliance:
  RDS offers encryption, IAM integration, audit logging, and VPC support out of the box. EC2 demands a custom configuration to achieve similar compliance.

For the connection guide to RDS MS-SQL server, please refer to this resource here. 

When EC2-Based SQL Server May Be Preferred

Full administrative control over the OS or SQL Server is needed.
Certain SQL Server features not available in AWS RDS are required.
Cost-sensitive dev/test environments.
In-house expertise is available to manage availability, backups, and licensing.

Conclusion

While the upfront cost of AWS RDS (Multi-AZ) is higher, it delivers major operational advantages—automated high availability, backups, patching, simplified licensing, integrated monitoring, and comprehensive AWS support. For critical production environments where uptime, scalability, and supportability are key, RDS offers a more reliable and low-maintenance solution.