SAP-C03 practice question: Cost-optimized compute and rightsizing (Graviton, Compute Optimizer)
Cost-Optimized Architecture Design A free question from our original SAP-C03 practice exam. Try it, then open the answer to see why each option is right or wrong.
A streaming site runs its video-encoding workers on a fleet of general-purpose x86 instances. The fleet runs at a low average CPU load, and AWS Compute Optimizer has recommended a smaller and cheaper instance option. The fleet has about 300 instances.
The build pipeline already produces container images for both x86 and arm64. Each encoding job runs for several hours and cannot checkpoint, so an interrupted job must start again, and the nightly window has no spare time.
The team wants the cost reduction without changing the encoding output.
Which action meets these requirements?
Choose one answer.
AA. Keep the x86 instances and buy more Savings Plans for them, so the same hourly spend covers a larger fleet at a lower rate.
BB. Move the encoding workers to Spot Instances across every Availability Zone, using a capacity-optimized allocation strategy and several instance types to reduce interruptions.
CC. Move the workers to the largest instance type in the family, so each job finishes sooner and the fleet can be reduced to a few machines.
DD. Review the Compute Optimizer recommendations, test the encoding jobs on Graviton instance types with the arm64 images, and move the fleet once the output matches.
Show the answer and explanation
Answer: D
A. Wrong: Savings Plans reduce the rate on the instances already in use but do not reduce how many instances are needed. The fleet is oversized, and that waste continues.
B. Wrong: Spot lowers the hourly rate, but an interruption restarts a multi-hour job that cannot checkpoint, and the nightly window has no room for reruns. It also leaves in place the oversizing that Compute Optimizer found.
C. Wrong: Larger instances cost more per hour, and a few oversized machines do not fix the low utilization. The change increases spend rather than reducing it.
D. Right: Correct. Graviton instances give better price performance for many workloads, and Compute Optimizer identifies the right size from observed load. Testing against the existing output confirms the encoding results before the move.
Explanation
Compute Optimizer's sizing advice combined with Graviton, tested against the arm64 images, lowers the cost without changing the output. Buying more Savings Plans keeps the waste, and bigger or Spot instances do not fix the oversizing.
Want more on Cost-optimized compute and rightsizing (Graviton, Compute Optimizer)? The 5 full-length practice sets have 5 more Cost-optimized compute and rightsizing (Graviton, Compute Optimizer) questions, 375 in all, none of them in the free exam. One payment of $14.99, no subscription. See the practice sets →