3 min readJun 2, 2025

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📌 Introduction

When architecting cloud solutions, one of the most overlooked but crucial factors is storage latency. In AWS, multiple storage services cater to different use cases — from low-latency block storage to highly scalable object storage.

But how do their latency profiles compare? And more importantly — which one should you choose for your specific workload?

In this post, I’ll break down the real-world latency differences between popular AWS storage services like EBS, EFS, FSx, S3, and Instance Store — with practical use cases for each.

📊 AWS Storage Services — Latency Comparison Table

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📌 Why Do These Latencies Differ?

Each AWS storage service is optimized for a specific access pattern and performance profile. Here’s a brief on why their latencies vary:

• Instance Store: Direct NVMe SSD attached locally to the instance — no network hop, hence ultra-low latency.
• EBS: Network-attached block storage — optimized for consistent sub-millisecond latency with io2 Block Express volumes.
• EFS: Managed file system over NFS protocol — involves network call and shared access overhead.
• FSx for Lustre: HPC-grade file system designed for high concurrency and parallelism — low latency, optimized for large-scale data processing.
• FSx for Windows: Similar to EBS with SMB protocol overhead — slightly higher latency than block storage.
• S3: Object storage accessed via HTTPS APIs — involves more networking layers and metadata lookup per object.

📌 Visual Latency Spectrum

A simple way to visualize this:

Instance Store < FSx for Lustre ≈ EBS io2 < FSx for Windows < EFS < S3

📌 Real-World Use Cases — When to Choose What

ScenarioRecommended StorageHigh-speed ephemeral storageInstance Store (NVMe)Ultra-low latency databasesEBS io2 Block ExpressShared POSIX-compliant file storageEFS (Provisioned mode)HPC, ML training, and Big DataFSx for LustreWindows file shares and SMB workloadsFSx for Windows File ServerMassive object storage with scalabilityS3 (Standard)

📌 Pro Tip: Benchmark It Yourself 🚀

Want to measure real latencies in your AWS region? Use this quick setup:

• Launch EC2 instance
• Attach EBS volumes (gp3, io2)
• Mount EFS and FSx file systems
• Use fio tool for IOPS and latency testing
• Use curl or AWS SDK for S3 GET/PUT latency measurements

If you’d like, I can share a Terraform + bash script combo for automated setup and benchmarking. Drop a comment if you want that! ✌️

📌 Conclusion

Latency matters. A lot. Especially for workloads like databases, analytics, and high-frequency applications. Understanding the AWS storage service latency spectrum helps you make data-driven architecture decisions and optimize both performance and cost.

So next time you pick a storage backend in AWS, don’t just go by capacity or price — consider latency too.

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Cheers! Harikrishnan M | Cloud DevOps Engineer