When setting up cloud infrastructure, cost optimization is an important issue for companies. AWS offers various ways to reduce operating costs, with AWS Savings Plans (SPs) and Reserved Instances (RIs) being two major cost-saving options. This article explores the differences between the two to help businesses make informed decisions when choosing.。
What are Savings Plans (SPs)?
With AWS Savings Plans, you don't buy physical instances but commit to purchasing on-demand instances at a discounted rate for one or three years. This discount can be up to 72% off the normal on-demand price.
Here is AWS showing how Savings Plans works：
AWS offers three types of Savings Plans: EC2 Instance Savings Plans, Compute Savings Plans, and Amazon SageMaker Savings Plans. Each plan applies to its named usage type. For example, Compute Savings Plans are suitable for AWS Lambda, Amazon EC2, and AWS Fargate usage.
What are Reserved Instances (RIs)?
AWS Reserved Instances (RIs) are a discounted pricing model that allows organizations to save up to 75% on on-demand instance fees when purchasing instances in advance for a fixed term of one or three years.
RIs allow you to "reserve" a certain amount of computing capacity in advance and prepay. There are three payment options:
- All Upfront Reserved Instances (AURI)
- Partial Upfront Reserved Instances (PURI)
- No Upfront Reserved Instances (NURI)
Savings Plans (SPs) vs. Reserved Instances (RIs)
AWS Savings Plans (SPs)
| AWS Reserved Instances (RIs)
| |
| Description | Commit to a certain level of computing capacity for one or three years, with discounts of up to 72% on Amazon EC2 usage. | Commit to a specific level of computing capacity in a certain AWS region and instance family for a discounted hourly rate, saving up to 75% on Amazon EC2 usage. |
| Types | Compute Savings Plans, EC2 Instance Savings Plans, Amazon SageMaker Savings Plans | Convertible Reserved Instances, Standard Reserved Instances |
| Potential Savings | Compute Savings Plans can save up to 66%, EC2 Instance Savings Plans up to 72%. Generally, a one-year commitment can save 40%, and a three-year commitment can save 60%. | Convertible Reserved Instances can save up to 66%, Standard Reserved Instances up to 72%. Generally, a one-year commitment can save 31%, and a three-year commitment can save 54%. |
| Applies to | Amazon EC2 instances (Compute Savings Plans apply regardless of instance family, operating system, AWS region, instance size, or tenancy). EC2 Instance Savings Plans apply to specific AWS regions and instance families. | Amazon EC2 instances that must match your current instances. |
| Capacity Reservation | Not offered by default, but you can reserve capacity through On-Demand Capacity Reservations. | Provides capacity for a specific Availability Zone by default. Convertible Reserved Instances can be exchanged or modified, while Standard Reserved Instances can be modified but not exchanged. |
| Ideal Usage Scenario | Relatively stable usage with occasional changes in instances. | Stable and predictable usage with the same instances. |
Conclusion
Both AWS Savings Plans and Reserved Instances are effective ways to reduce costs in AWS operations, but they differ in terms of flexibility and pricing structure. Businesses should evaluate their specific needs, considering factors like computing capacity, instance type variability, and willingness to prepay. With a comprehensive evaluation, you can develop the cost-saving strategy that best suits your business needs.
Source：https://www.cloudzero.com/blog/savings-plans-vs-reserved-instances/