What the hell are USB-C 3.2 Generations 1, 2 & 2x2?

September 2019

USB-A, USB-B, USB 3.0, USB 2.0, USB-C, USB-Q (ok I made up that last one), there are so many types of USB connections on the market. The Universal Implementers Forum recently threw a huge curveball in their common-sense naming system by opting to rename their standards and use terms like “USB C 3.2 Gen 2x2”.

But what is “USB C 3.1 Gen 2”?... Well Maplin can help you with that!

USB A, B & C

For the uninitiated, the A, B, C (and my USB Q connector, if any companies are interested), alludes to the physical connector itself. USB Type-A is your bog-standard USB port you’re used to seeing on USB sticks, the back of your TV, and modern laptops (sorry Mac users).

You may have noticed that the inner part can come in different colours. Sometimes the colour is an aesthetic feature, often it’s an indicator of the port/cables speed rating. For example, the blue bit (technical term), generally indicates that a device/cable is capable of running at USB 3.0 speeds.

Picture 1: USB Flash drive with a USB-A Connector (USB 3.0)

There are currently two variants of USB B connector, one for USB 2.0 and one for USB 3.0. You’ll often find these connectors on the back of printers (it’s the funny square one).

 

Picture 2 + 3: USB B 2.0 variant (left) & USB B 3.0 variant (right)

The USB C connector is the first reversable USB connector, making it the common-sense choice for mobile devices. USB C is the swiss army knife of USB C connectors, supporting DisplayPort, Thunderbolt, and HDMI standards without an adapter (Note: Not all devices/cables support these standards).

Picture 4: USB C connector

But where does the “Gen 2” come in?

Where letters are used to label the physical connectors, numbers are used to label the speeds. The USB Implementors Forum (USB-IF) sometimes use different terms to the ones seen on products and recently they changed some of their terminology.

The chart below includes both the USB-IF’s naming system and the names you’re probably more familiar with.

Common Term


USB 1.0

 


USB 2.0


USB 3.0

 


USB 3.1

 


USB 3.2


USB 4

USB-IF Internal Term


USB 1.0

 


USB 2.0


USB 3.2 Gen 1

(Previously USB 3.1 Gen 1)


USB 3.2 Gen 2

 


USB 3.2 Gen 2x2


USB4

USB-IF Marketing Term/s


Basic Speed

 


Hi-Speed


SuperSpeed USB

 


SuperSpeed USB 10Gbps

(aka SuperSpeed USB+)


SuperSpeed USB 20Gb/s


USB4 20Gbps

USB4 40Gbps

Release Year*


1994

 


2000


2011

 


2014

 


2017


2019

Maximum Speed


1.5Mbit/s (Low Speed)

12Mbit/s (Full Speed)


480 Mbit/s


5Gbit/s

 


10Gbit/s

 


20Gbit/s


20Gb/s

40Gb/s

* Release year of the specifications

Table 1: USB Versions & Speeds

E-Marker IC Chip

For a USB-C cable to carry data at 5 Gbit/s (USB 3.2 Gen 2 aka USB 3.1) or more, a chip known as the E-Marker chip must be installed inside one of the USB connectors. The chip tells the device the rated data performance of the cable, as well as communicating the amount of power it can safely transmit.

Recommendation

The changes in terminology by the USB Implementers Forum could technically result in USB 3.0 cables being sold as USB 3.2 cables.

 

Maplin recommends checking the rated speed of USB cables when making a purchase to avoid disappointment.