EBS Volume Types: A Simple Guide for Everyone
5 min read
If you're using AWS and wondering which storage to pick for your EC2 instance, chances are you've come across EBS – short for Elastic Block Store. And then, you hit a wall: gp2? gp3? io2? Cold HDD? It’s like choosing a car when you’re not even sure if you need an SUV or a sports coupe.
Don’t worry. In this blog, we’ll break down EBS Volume Types in the simplest way possible, with real-world analogies and clear use cases – so by the end, you’ll know exactly what to use and why.
🧠 First, Some Jargon Made Simple
Before we get into volume types, let's understand some key terms that AWS uses when describing EBS performance.
🔁 What is IOPS?
IOPS stands for Input/Output Operations Per Second. It's a measure of how fast your storage can read or write small blocks of data.
🧾 High IOPS = better for tasks that read/write small files rapidly (like databases).
Think of IOPS like how many times per second your disk can "fetch or write a page".
🚚 What is Throughput?
Throughput measures how much data can be moved in or out of the volume per second, typically in MB/s (megabytes per second).
- 📦 It’s ideal for big, sequential file transfers, like video files or log archives.
⏱️ What is Latency?
Latency is the delay between sending a request and getting a response.
⏳ Low latency = faster response time.
Essential for interactive apps or transaction-heavy workloads.
📦 The 5 EBS Volume Types (As of 2025)
1. gp3 – General Purpose SSD (The Smart Default)
🏎️ IOPS: 3,000 baseline, up to 16,000 (independent of volume size)
🚚 Throughput: Up to 1,000 MB/s
⏱️ Latency: Low
💲 Cost: More efficient and cheaper than gp2
🧰 Use Case: Web servers, app servers, boot volumes, medium-size databases
Why use gp3?
It’s fast, consistent, and cost-effective. You can tweak IOPS and throughput separately from storage size.
Analogy: Like a modern hybrid car – fuel efficient, performs well, and suitable for most drivers.
2. gp2 – General Purpose SSD (The Legacy Pick)
🔁 IOPS: Scales with size (100 IOPS per GB), up to 16,000
🚚 Throughput: Max 250 MB/s
💸 Cost: Not as cost-efficient as gp3
🧰 Use Case: Still in use for older setups
Why use gp2?
Mostly if your workloads already use it or for backward compatibility. For new deployments, gp3 is better.
Analogy: Like a reliable old car – it works, but it’s not the most cost-effective choice anymore.
3. io2 / io2 Block Express – Provisioned IOPS SSD
🔁 IOPS: Up to 256,000
🚚 Throughput: Up to 4,000 MB/s (Block Express)
💎 Durability: 99.999% (highest among EBS types)
🧰 Use Case: Critical enterprise databases like SAP HANA, Oracle, PostgreSQL
💰 Cost: Premium pricing
Why use io2?
When milliseconds matter, like in high-performance databases or financial transactions.
Analogy: Like a high-performance race car – powerful, precise, but pricey.
4. st1 – Throughput Optimized HDD
🔁 IOPS: Around 500 per volume (burstable)
🚚 Throughput: Up to 500 MB/s
🧰 Use Case: Big data, analytics, data lakes, log processing
💲 Cost: Lower cost per GB than SSDs
Why use st1?
Great for large files accessed sequentially – not good for small, random reads/writes.
Analogy: Like a cargo ship – slow and steady, but great for moving bulk data.
5. sc1 – Cold HDD
🔁 IOPS: Up to 250
🚚 Throughput: Up to 250 MB/s
🧰 Use Case: Archiving, backups, infrequently accessed data
💰 Cost: Lowest cost per GB
Why use sc1?
Perfect for "write once, read rarely" scenarios. Definitely not for active applications.
Analogy: Like storing old furniture in a basement – cheap, and you only go down there once in a while.
🧮 Quick Comparison Table
| Volume Type | Type | Max IOPS | Max Throughput | Latency | Best For | Cost |
| gp3 | SSD | 16,000 | 1,000 MB/s | Low | General workloads | $$ |
| gp2 | SSD | 16,000 (size-dependent) | 250 MB/s | Low | Legacy systems | $$+ |
| io2 | SSD | 256,000 | 4,000 MB/s | Ultra-low | Databases | $$$$ |
| st1 | HDD | ~500 | 500 MB/s | Higher | Analytics & logs | $ |
| sc1 | HDD | ~250 | 250 MB/s | Highest | Archives & backups | $ (lowest) |
🧭 How to Choose Wisely?
Start with gp3 unless your app screams for something else.
Go for io2 if your database is the beating heart of your business.
Use st1 for large-file, read-heavy jobs.
Use sc1 for cheap storage that you rarely touch.
Avoid gp2 for new apps unless required.
🧠 Wrapping Up
Choosing the right EBS volume type is crucial for performance and cost efficiency. But now that you know what IOPS and throughput mean, and how each volume behaves, you're in a great position to make the right decision.