AWS Amazon EC2 Reserved Instances Optimization

For certain services like Amazon EC2 and Amazon RDS, you can invest in reserved capacity. With Reserved Instances, you can save up to 75% over equivalent on-demand capacity. Reserved Instances are available in 3 options – All up-front (AURI), partial up-front (PURI) or no upfront payments (NURI).

Rule Description

Rule Code: AWS-RI-02

A significant part of using AWS involves balancing your Reserved Instance (RI) usage and your On-Demand instance usage.

We provide recommendations on which RIs will help reduce costs incurred from using On-Demand instances. AWS generates these recommendations by analyzing your On-Demand usage for the past 30 days, and then categorizing the usage into eligible categories for reservations.

We then simulate every combination of reservations in the generated category of usage in order to identify the best number of each type of RI to purchase to maximize your savings.

This check covers recommendations based on Standard Reserved Instances with partial upfront payment option.

Audit / Verification

When you buy Reserved Instances, the larger the upfront payment, the greater the discount. To maximize your savings, you can pay all up-front and receive the largest discount. Partial up-front RI's offer lower discounts but give you the option to spend less up front. Lastly, you can choose to spend nothing up front and receive a smaller discount, but allowing you to free up capital to spend in other projects.

Standard and Convertible Reserved Instances Pricing

Purchase Convertible Reserved Instances if you need additional flexibility, such as the ability to use different instance families, operating systems, or tenancies over the Reserved Instance term. Convertible Reserved Instances provide you with a significant discount (up to 66%) compared to On-Demand Instances and can be purchased for a 1-year or 3-year term.

Reserved Instances Payment Options

You can choose between three payment options when you purchase a Standard or Convertible Reserved Instance.

  • With the All Upfront option, you pay for the entire Reserved Instance term with one upfront payment. This option provides you with the largest discount compared to On-Demand Instance pricing.
  • With the Partial Upfront option, you make a low upfront payment and are then charged a discounted hourly rate for the instance for the duration of the Reserved Instance term.
  • The No Upfront option does not require any upfront payment and provides a discounted hourly rate for the duration of the term.

By using reserved capacity, your organization can minimize risks, more predictably manage budgets, and comply with policies that require longer-term commitments.

Instance Size Flexibility

All Regional Linux/UNIX RIs with shared tenancy now apply to all sizes of instances within an instance family and AWS region, even if you are using them across multiple accounts via Consolidated Billing. This will further reduce the time that you spend managing your RIs and will let you be even more creative and innovative with your use of compute resources.