USB Speeds Explained: USB 1.0 to USB4 (A+ Cheat Sheet)

 USB Speeds

USB 2.0, also known as Hi-Speed USB, has a maximum data transfer speed of 480 megabits per second (Mbps).

Here are the maximum data transfer speeds for some other USB standards:

USB 1.0/Low-Speed: 1.5 Mbps

USB 1.1/Full-Speed: 12 Mbps

USB 3.0/SuperSpeed: 5 gigabits per second (Gbps) labeled as SS (SuperSpeed) on the PC

USB 3.1/SuperSpeed: 10 Gbps labeled as SS+ on the PC

USB 3.2 renamed the existing standards and added a new tier: Gen 1 (5 Gbps, formerly USB 3.0/3.1 Gen 1), Gen 2 (10 Gbps, formerly USB 3.1 Gen 2), and the new Gen 2x2 (20 Gbps, which requires a USB-C connector and cable on both ends).

USB4 pushes speeds further to 40 Gbps (USB4 Version 2.0 can reach 80 Gbps), is built on the Thunderbolt 3 protocol, and requires a USB-C connector.

USB 2.0 devices can also provide a power output of up to 500 milliamps (mA) at 5 volts. 

USB 2.0

USB 3.0 & 3.1

USB 2.0 Type B & Type B Micro are not compatible with 3.0

Exam Tip: USB speed names have been renamed more than once (today's USB 3.2 Gen 1 is the same 5 Gbps link as the original USB 3.0 and USB 3.1 Gen 1), so for the A+ exam it's safer to key off the actual speed and SS/SS+ markings than the version number alone. Also remember that a cable and both connectors all have to support a given standard — the link only runs as fast as its slowest component.