USB-C explained: what is USB-C?

Below we will explain USB-C / USB Type-C and the advantages and applications of this standard. First, we will explain more about USB4®, the latest generation.


The advantages of USB4®:

  • Always a USB-C connector
  • Data transfer speed: 20Gbps or 40Gbps
  • Supports Thunderbolt™3 or Thunderbolt™4
  • DisplayPort Alternate Mode (DP Alt Mode) support 1x 8K @ 60Hz or 2x 4K @ 60Hz
  • Extended Power Range (EPR) adds the Power Delivery profiles: 28V, 36V and 48V for charging up to 240W

Do you need USB-C Active Optical Cables (AOC) for connections over long distances?

Learn more about the USB-C AOC cable, or Active Optical Cable and how it differs from regular copper USB-C cables. 

read more

USB4® 20Gbps and USB4® 40Gbps

USB4® 20Gbps is also known as USB 3.2 Gen 2x2 (two lanes of 10Gbps). USB4® 20Gbps is compatible with Thunderbolt™3. USB4® 40Gbps doubles the speed of USB4® 20Gbps and supports Thunderbolt™3 and Thunderbolt™4.


USB4® and Thunderbolt™4 have a lot in common but they are not exactly the same. They both support 40Gbps, power passthrough, video, audio and they share the USB Type-C connector.
When searching for the ultimate performance Thunderbolt™4 is the best option. E.g. Thunderbolt™4 requires a laptop that supports Thunderbolt™4 and also the requirements of the peripherals are higher.

Power Delivery / EPR: 240W

The Extended Power Range (EPR) adds additional Power Delivery profiles to a USB4® cable: 28V, 36V and 48V. With 48V a maximum of 240W can be transferred through a cable. USB-C cables that use SPR (Standard Power Range) only can deliver 60W.

DisplayPort Alternate Mode protocol

The ACT USB4® 40Gbps cable support the DisplayPort Alternate Mode (DP Alt Mode) protocol: one 8K @ 60Hz monitor or two 4K @ 60Hz monitors in the daisy chaining setup.

Officially USB-IF certified

Did you know that ACT is member of the USB Implementers Forum, Inc.? The ACT USB4® cables are officially certified by the USB-IF corporation. This means that the USB4® cables are tested to the highest standards by USB-IF. You can find the official USB-IF logo on the connector.

An overview of our officially USB-IF certified cables:

USB-C USB4® 40Gbps cable

  • USB-IF certified
  • Data transfer speed up to 40Gbps
  • Extended Power Range (EPR): 48V @ 5A = 240W
  • Thunderbolt™3 and Thunderbolt™4 support
  • 0.8 meters

USB-C USB4 20Gbps cable

  • USB-IF certified
  • Data transfer speed up to 20Gbps
  • Extended Power Range (EPR): 48V @ 5A = 240W
  • Thunderbolt™3 support
  • 1 meter


USB-C 3.2 cable

  • USB-IF certified
  • Data transfer speed up to 5Gbps
  • Max. power throughput 20V @ 3A = 60W
  • 1 meter


USB-C 3.2 cable

  • USB-IF certified
  • Data transfer speed up to 5Gbps
  • Max. power throughput 20V @ 3A = 60W
  • 2 meters


Other USB generations

We want to explain other USB generations. A common thought is that USB 3.2 is the same as USB-C. The main reason for this association is that USB 3.2 was equally released with the USB-C standard.
USB 3.2 has two versions: USB 3.2 Gen1 and USB 3.2 Gen2. Gen1 has a maximum speed of 5Gbit/s and Gen2 a maximum speed of 10Gbit/s. USB 3.2 Gen1 is also called USB 3.1, USB 3.0 or SuperSpeed. SuperSpeed+ is the name of USB 3.2 Gen2.
USB 2.0 is also a well-known version. It is the predecessor of USB 3.2 and has a maximum speed of 480Mbps. HighSpeed is the other name for USB 2.0.

USB-C: the advantages

  • Small symmetrical and reversible connector
  • Charge faster and safer with Power Delivery (PD)
  • Thunderbolt™3 support: images and power via ONE cable
  • DisplayPort Alternate Mode support

A compact reversible connector

Always struggling with USB-A cables? When connecting a USB-A plug into your computer, you always try the wrong side first. Always! The USB-C connector doesn’t have a top or bottom side. Plug the connector either way into your device. The other big advantage of this connector is its compact size. This makes new laptops, smartphones and other devices with USB-C smaller and more light-weight.  
Attention: the protocols below aren’t supported by every device. Please check the manual of the device for more information about the supported protocols. 

Power Delivery: charge faster AND safer

USB-C can support Power Delivery (PD). This protocol enables your smartphone to charge up to 70% faster than by using a normal charger. One footnote: both the charger and the connected device must support Power Delivery. They both need built-in chips that communicate with each other to decide the best PD profile. Is a USB-C accessory connected between the charger and the device? This USB-C accessory will communicate as well with the charger and the device.

USB-C with Power Delivery enables charging in two directions. E.g. you can charge your smartphone with your tablet but also your tablet with your smartphone.

The following profiles are available: 5V, 9V, 12V, 15V and 20V.

Thunderbolt™ 3 support

One can name Thunderbolt™ 3 in the same line with USB-C. Older Thunderbolt™ versions are using their own interface. The third Thunderbolt™ generation is using USB-C: one connection for multiple protocols: USB-C. Convenient right?!

The throughput speed up to 40Gbit/s is the biggest advantage of Thunderbolt™ 3. This is four times faster than the throughput of USB 3.2 Gen2: 10Gbits/s. Besides, Thunderbolt™ 3 provides power and images to two 4K screens of max. 60Hz. All used peripherals, like a laptop, screens and cables, must support Thunderbolt™ 3.

DisplayPort Alternate Mode (DP Alt mode) for connecting (4K) monitors

USB Type-C supports DisplayPort Alternate Mode (DP Alt Mode). This makes it possible to transfer (4K) videos simultaneously with data and power.

Which technology or protocol does my USB-C laptop support?

Each technology/protocol has its own logo. In the best case these logos are visible next to the USB-C port on your laptop. The only thing is that suppliers aren’t obligated to put the logos on the laptop. No symbol next to the USB-C port on your laptop? Please consult the manual of the laptop’s supplier to check which technology/protocol this Type-C port supports.

USB-C: intelligent chip (e-marker)

E-marker: An intelligent chip that takes care of fast charging possibilities. A DFP (Downstream Facing Port) determines via the e-marker chip which features are supported. Like: fast charging via Power Delivery (PD), Thunderbolt™3 or DisplayPort Alternate Mode (DP Alt Mode). Active cables and converters: each cable end can have a different active function. All active USB-C cables need an e-marker chip to restore the USB signals. This is the case with USB booster cables.

USB-C: one cable for all applications?

You can use a cable with USB-C connector for every purpose (charging/data transfer), right? Nothing could be further from the truth. The quality of a USB-C cable can be completely different than the quality of another USB-C cable. It is of great importance to use qualified cables to prevent irreparable damage to your valuable equipment. What are the qualities of a good cable:
The most important factor is the connector. This connector must have a seamless design.
Some manufactures are recommending some cables that can be safely used.
Charging your laptop requires a more powerful cable and a plain data cable. Please pay attention to this!

What is MST (Multi Stream Transport)?

MST is part of the DisplayPort 1.2 standard, with which monitors and computers can support 'daisy-chaining'. Usually, you recognize daisy-chaining when the monitor has both a DisplayPort input and output. Connect the first monitor to the computer and the second monitor to the first monitor. If both the monitor and the computer support MST daisy-chaining, the two screens work as separate screens. As if they both were connected directly to the computer.


Within USB-C it is possible that DP-alt mode (DisplayPort alternate mode) is supported by your laptop / PC. If this is the case it will also support MST. You can choose to use a USB-C to MST adapter. This adapter has multiple video outputs that can be used to have multiple monitors (even if they don't support MST ) to connect to a MST (daisy chain). The connected screens can now be recognized as separate screens on your laptop / PC and be used as an extended desktop.

MST on macOS

Please note: macOS does not support MST Daisy chaining. macOS only supports Daisy-chaining with the Thunderbolt™ 3 and Thunderbolt™ 4 standard. The MST adapters will not provide the desired result for macOS devices. The connected screens in this case, only show a clone (copy) of your main screen on the connected screens. Also called SST (Single Stream Transport).