A high level guide to USB-C

What is USB-C?

USB-C is a connector designed by USB-IF. USB-C’s popularity comes from its large feature set and reversibility, creating a promise of using one cable for all smart devices. Billions of devices already have USB-C connectors and the European Union is enforcing the connector for all mobile devices by the end of 2024. A byproduct of this legislation is the iPhone’s switch to USB-C. This means the billion iPhone users, a new cable will fall into their hands.

Although the connector is quickly becoming universal, specifications regarding USB-C connectors and cables still have long ways to go.

Evolution of USB connectors

Evolution of USB connectors

A Rundown

A USB-C connector may offer the following features through its 24 pins:

  • Power
  • Data Transfer
  • Video
  • Audio
  • Ethernet

Because not every device needs every possible feature that USB-C provides, device manufacturers can save costs by only enabling the required features on the connector. In many cases, only power or data transfer is required. For example, a PlayStation controller doesn’t need to transmit a video signal from its USB-C port so video functionality can be omitted. On the other hand, a laptop’s USB-C port may support both video and power so users can connect to a monitor and charge their laptop with the same USB-C port.

The same is true for USB-C cables. Not all USB-C cables are capable of every listed feature. As a consumer, you have control of which USB-C cable best fits your needs.

Unfortunately, this isn’t so black and white. Within these features, USB-C cables can offer different levels of the same feature.

Power

For example, all USB-C cables are capable of supplying devices with up to 5 watts of power but this is where the common ground ends. USB-C cables may support Power Delivery (PD) and can deliver up to 240 watts of charging. But despite 240W being the maximum wattage, many USB-PD cables are limited to just 60W or 100W.

Data Transfer

All USB-C cables are also capable of transferring data between devices but at differing rates. USB-IF has recently adopted a new cable naming convention based on the cable’s transfer rate, making it clear how much data can be transferred per second. But it wasn’t always so easy, the table below shows the previous iterations of cable names since many cables today have yet to adopt the new naming convention.

NewOldOlder
USB 5 GbpsUSB 3.0USB 3.1 Gen 1
USB 10 GbpsUSB 3.1USB 3.1 Gen 2
USB 20 GbpsUSB 3.1 Gen 2x2USB 3.2 Gen 2
USB 40 GbpsUSB 3.2 Gen 2x2USB 3.2
USB 80 GbpsUSB 4 Version 2---

Video

A cable’s ability to transmit a video signal depends on how much data it’s capable of transferring. The following chart is a breakdown of the video signal supported based on a cable’s transfer rate.

Transfer RateVideo Output Supported
USB 5 Gbps1080p@60Hz
USB 10 Gbps1080p@144Hz
1440p@60Hz
USB 20 Gbps4k@60Hz
1440p@120Hz
USB 40 Gbps4k@144Hz
8k@60Hz

Other specifications

In reality, shopping for a USB-C cable may not be as easy as just searching for the combination of levels of specifications you need.

A quick Amazon search will yield results for thousands of cables seemingly indistinguishable from one and another. On closer inspection, you will encounter various terms previously not mentioned such as USB4 and Thunderbolt 3 and 4 which all share the same USB-C connectors. These cables are required to have a minimum feature set established by USB-IF or Thunderbolt.

SpecificationFeature Set
USB4At least 1 display
20 Gbps data transfer
Thunderbolt 3At least 1 4k@60Hz display
40 Gbps data transfer
Thunderbolt 4At least 1 8k@60Hz display or 2 4k@60Hz displays
40 Gbps data transfer

These cables may also be labeled USB-IF certified for USB4 cables or Intel certified for Thunderbolt 3 and 4 which ensures that the cable actually meets the specification’s requirements.

Finding your cable

Still processing all of that information? Save yourself the stress and take our cable match quiz here.


Sources

"Frequently Asked Questions (Faqs): Thunderbolt Technology Community.” Thunderbolt, https://www.thunderbolttechnology.net/tech/faq.

“It's 2022 and USB-C Is Still a Mess.” Android Authority, 17 Oct. 2022, https://www.androidauthority.com/state-of-usb-c-870996/.

“USB Type-C® Cable and Connector Specification.” USB-IF, https://usb.org/usb-type-cr-cable-and-connector-specification.

“What's the Difference between Thunderbolt 3, Thunderbolt 4, and USB4.” Plugable Technologies, https://plugable.com/blogs/news/what-s-the-difference-between-thunderbolt-3-thunderbolt-4-and-usb4