SAA-C03 Design High-Performing Architectures Practice Question
A team runs a latency-sensitive service on EC2 and needs consistent, low-latency block storage for a database. The application requires predictable performance and should be fast for random reads/writes. Which EBS volume type is the best choice?
⚠ Common exam trap
A common mix-up: candidates confuse throughput-optimized HDDs (st1) with low-latency needs, mistakenly thinking 'throughput' implies fast performance, when in fact HDDs are unsuitable for random I/O and latency-sensitive workloads.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
EBS gp3 (general purpose SSD)
B is correct because gp3 is a general-purpose SSD that provides consistent, low-latency performance for random read/write operations, making it ideal for latency-sensitive databases. It offers a baseline of 3,000 IOPS and 125 MB/s throughput, with the ability to independently scale IOPS up to 16,000 and throughput up to 1,000 MB/s, ensuring predictable performance without the burst-bucket limitations of gp2.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
EBS st1 (throughput optimized HDD)
Why it's wrong here
st1 targets throughput for workloads and is HDD-based, often with higher latency than modern general-purpose SSD. Random read/write latency consistency may not meet a strict low-latency requirement. It is usually better for larger sequential throughput needs.
When this WOULD be correct
For a big data processing application that performs large, sequential reads/writes (e.g., log processing, data warehousing) and requires high throughput at low cost, st1 would be the best choice.
- ✓
EBS gp3 (general purpose SSD)
Why this is correct
gp3 is designed for a broad range of general-purpose workloads with solid low-latency performance. It supports random I/O patterns and offers predictable performance for many latency-sensitive applications. It is a common best-fit choice when you need balanced performance without specialized throughput-focused characteristics.
- ✗
EBS sc1 (cold HDD)
Why it's wrong here
sc1 is intended for infrequent access and is typically not appropriate for latency-sensitive random I/O. Cold HDD volumes prioritize cost over performance. It can increase latency variance, which would hurt interactive database workloads.
When this WOULD be correct
A question asking for the most cost-effective EBS volume type for storing large amounts of infrequently accessed data, such as archival logs or backup files, where throughput is not a priority.
- ✗
EBS magnetic (legacy magnetic)
Why it's wrong here
Magnetic volumes are generally legacy and provide poor performance for random, latency-sensitive operations. They are not suitable for predictable low-latency database storage. Modern EBS SSD options like gp3 are the recommended alternative.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The SAA-C03 exam frequently reuses these exact scenarios with slightly different constraints.
✓EBS gp3 (general purpose SSD)Correct answer▾
Why this is correct
gp3 is designed for a broad range of general-purpose workloads with solid low-latency performance. It supports random I/O patterns and offers predictable performance for many latency-sensitive applications. It is a common best-fit choice when you need balanced performance without specialized throughput-focused characteristics.
✗EBS st1 (throughput optimized HDD)Wrong answer — click to see why▾
Why this is wrong here
EBS st1 is a throughput-optimized HDD volume designed for large, sequential workloads, not for low-latency random reads/writes required by a database.
★ When this WOULD be the correct answer
For a big data processing application that performs large, sequential reads/writes (e.g., log processing, data warehousing) and requires high throughput at low cost, st1 would be the best choice.
Why candidates choose this
Candidates may confuse 'throughput optimized' with 'low latency' or assume HDD volumes are sufficient for database workloads without considering the need for consistent, low-latency random I/O.
✗EBS sc1 (cold HDD)Wrong answer — click to see why▾
Why this is wrong here
EBS sc1 (cold HDD) is designed for infrequently accessed, cold data with low throughput requirements, not for low-latency, high-performance random reads/writes needed by a database.
★ When this WOULD be the correct answer
A question asking for the most cost-effective EBS volume type for storing large amounts of infrequently accessed data, such as archival logs or backup files, where throughput is not a priority.
Why candidates choose this
Candidates may confuse 'cold' with 'low latency' or think that any HDD can handle database workloads, overlooking the specific performance characteristics of sc1.
Analysis generated from the official SAA-C03blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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About these practice questions
This SAA-C03 question is part of Courseiva's 302-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on SAA-C03
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A team runs a latency-sensitive service on EC2 and needs consistent, low-latency block storage for a database. The application requires predictable performance and should be fast for random reads/writes. Which EBS volume type is the best choice?
easy- A.EBS st1 (throughput optimized HDD)
- ✓ B.EBS gp3 (general purpose SSD)
- C.EBS sc1 (cold HDD)
- D.EBS magnetic (legacy magnetic)
Why B: B is correct because gp3 is a general-purpose SSD volume that provides consistent, low-latency performance for random read/write operations, making it ideal for latency-sensitive database workloads. It offers a baseline of 3,000 IOPS and 125 MB/s throughput, with the ability to independently scale up to 16,000 IOPS and 1,000 MB/s, ensuring predictable performance without the burst-bucket limitations of gp2.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SAA-C03 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SAA-C03 exam.