AWS Certified Solutions Architect – Associate (SAA-C03)Design Cost-Optimized ArchitecturesMedium
A research institution uses a large number of Amazon EC2 instances for scientific simulations. These simulations are computationally intensive and run continuously for several months. The institution has a limited budget and wants to achieve the lowest possible cost for their compute resources. Which EC2 purchasing option should they choose?
- AEC2 Instance Savings Plans
- BOn-Demand Instances
- CSpot Instances
- DDedicated Hosts
Show answer & explanationAnswer & explanation
Correct answer: A. EC2 Instance Savings Plans
EC2 Instance Savings Plans offer significant discounts (up to 72%) on EC2 instances in exchange for a 1-year or 3-year commitment to a consistent amount of compute usage (measured in $/hour). For 'continuously running' and 'computationally intensive' workloads over 'several months' with a 'limited budget', this provides the lowest cost while maintaining flexibility across instance families and regions.
Why the other options are wrong
- B. On-Demand Instances are the most expensive and would not meet the 'lowest possible cost' requirement for long-running workloads.
- C. Spot Instances offer even deeper discounts but are suitable only for interruptible workloads. Scientific simulations running 'continuously for several months' might not tolerate interruptions, making Spot too risky unless specifically designed for fault tolerance.
- D. Dedicated Hosts are for specific licensing or regulatory requirements and are generally more expensive than other options, not focused on achieving the 'lowest possible cost' for general compute.
EC2 Instance Savings Plans
EC2 Instance Savings Plans offer significant discounts (up to 72%) in exchange for a commitment to a consistent amount of compute usage (measured in $/hour) over a 1-year or 3-year term.
- Apply to EC2 usage regardless of instance family, OS, or Region (for EC2 Instance SP).
- Provide deeper discounts than Convertible RIs and comparable to Standard RIs.
- Offer more flexibility than RIs as they apply to compute usage, not specific instances.
- Ideal for steady-state workloads with flexible instance type needs.
Memory trick: Savings Plans: Steady Spend, Serious Savings.