---
id: external-drives.what-do-usb-version-names-mean
url: https://storagestudio.us/faq/external-drives/what-do-usb-version-names-mean
category: "External drives"
subcategory: "Speed, cables and hardware"
question: "What do USB 3.0, 3.1, 3.2 and USB4 mean when buying a drive?"
alt_questions:
  - "USB 3.2 Gen 2 vs Gen 2x2 explained"
  - "Difference between USB 3.1 and 3.2"
  - "Which USB version do I need for an external SSD?"
  - "USB4 vs Thunderbolt drive Mac"
  - "confusing usb names gen 1 gen 2"
short_answer: "They're USB generations with confusing, repeatedly changed names. Compare the speed in Gbps on the drive, cable and port instead — the slowest part sets the speed, and some top USB modes aren't supported by Mac ports."
tags: ["usb", "usb4", "buying", "speed"]
related: ["https://storagestudio.us/faq/external-drives/thunderbolt-or-usb-c-for-an-external-ssd", "https://storagestudio.us/faq/external-drives/does-the-cable-matter-for-an-external-ssd", "https://storagestudio.us/faq/external-drives/what-kind-of-external-drive-should-i-use-with-storage-studio"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What do USB 3.0, 3.1, 3.2 and USB4 mean when buying a drive?

They're generations of the USB standard, and the names have been changed several times, so the same speed can appear under different labels. Ignore the version number and look at the **speed in Gbps** printed on the drive, cable and port — that's what decides how fast a copy can go.

Rules of thumb for a Mac:

- The connection runs at the speed of the slowest part — drive, cable, hub or port.
- Some very fast USB modes aren't supported by Mac ports, so a drive advertised at the top USB speed may run slower on a Mac.
- USB4 and Thunderbolt drives work at their best on Macs with Thunderbolt or USB4 ports.

For choosing between the two families, see [Thunderbolt or USB-C](https://storagestudio.us/faq/external-drives/thunderbolt-or-usb-c-for-an-external-ssd).