Which solution will provide the MOST cost savings for all the organization’s compute usage?
Purchase Reserved Instances for the organization to match the size and number of the most common EC2 instances from the member accounts.
Purchase a Compute Savings Plan for the organization from the management account by using the recommendation at the management account level.
Purchase Reserved Instances for each member account that had high EC2 usage according to the data from the last 6 months.
Purchase an EC2 Instance Savings Plan for each member account from the management account based on EC2 usage data from the last 6 months.
Explanations:
Purchasing Reserved Instances (RIs) is beneficial for predictable usage; however, they are account-specific and do not provide flexibility for varying workloads across accounts. This can lead to underutilization if usage patterns change.
A Compute Savings Plan offers the most flexibility across different compute services (EC2, Fargate, Lambda) and provides cost savings based on overall organization usage. It accommodates unpredictable demand effectively over the next 3 years.
Buying Reserved Instances for each member account limits cost savings to only EC2 usage and may not account for variable workloads. This approach also does not maximize savings across the organization as a whole.
EC2 Instance Savings Plans are beneficial but limited to EC2 usage and do not offer the same level of flexibility as a Compute Savings Plan. This could lead to missed savings opportunities for other compute services utilized by the organization.
I organize that the answer is:
Purchase a Compute Savings Plan for the organization from the management account by using the recommendation at the management account level.