What is USB4?

Oct 23, 2020

   In September 2019, the connection standard "USB4" for various digital devices such as PCs and smartphones was announced. The full name is Universal Serial Bus Generation 4. So what is "USB4"? What is the difference with the current USB?
   USB4 is different from all other versions of USB. The new specification has no space before the version number. Although most people might write it as USB 4, the official name is USB4. This is different from the familiar USB 2.0, USB 3.0, USB 3.1, etc.

   The biggest change of the new USB4 is the integration of the Thunderbolt protocol specification donated by Intel to USB-IF. Through dual-link operation, the transmission rate has doubled to 40Gbps, and through the tunnelling transmission technology, Supports multiple data and display protocols, such as PCI Express and DisplayPort.

   USB4 has become the most complicated USB standard so far, you can read it yourself if you want to know the details: https://www.usb.org/document-library/usb4tm-specification

   Simply speaking, USB4 has the following obvious features:

   1. Data transfer rate: Based on the data transfer technology "Thunderbolt 3" jointly developed by Intel and Apple, the data transfer speed of USB4 is as high as 40 Gbps. The speed is twice that of the newly released USB 3.2 (Gen2×2), and it can transmit DisplayPort video at the same time. Designed to combine multiple protocols into a single physical interface, which can dynamically share the overall speed and performance of the USB4 architecture.
   2. Connector: USB4 only uses USB Type-C connector. The signal uses dual-channel transmission; the previous connectors, such as USB Type-A or Micro-B, only support single-channel transmission and cannot support USB4.
  3. Power supply: It can provide up to 100W power supply, which can realize power supply to high-power equipment and better power management.

  4. Compatibility: Compatible with lower versions, such as: USB 1.0, USB 2.0, USB 3.1, etc., and optionally compatible with "Thunderbolt 3"

  The USB 1.0 specification was released in 1996. The transmission speed supports low-speed 1.5 Mbps and full-speed 12 Mbps. Later, support speeds of 480 Mbps, 5Gbps, 10Gbps, 20Gbps, etc. have been released. The latest generation of USB4 specifications was released in September 2019, supporting 20 Gbps And 40 Gbps. Please refer to the figure below for the evolution of the USB interface and the corresponding logo.


   USB4 defines the 40Gbps standard, which can dynamically share bandwidth so that a single data cable can achieve multiple functions.

   With USB4, PCIe and display data can be transmitted on one cable at the same time, plus traditional USB functions and power supply (provided by USB PD), which is very convenient. In the future, most peripherals, including high-speed networks, external graphics cards, high-definition displays, large-capacity high-speed storage devices, and even one machine and another machine, can be interconnected through a Type-C interface. And if these devices implement USB4 Hub, you can also connect more devices in series or branch from these devices

   Although the USB Promoter Forum released the specifications of USB 4 in September 2020, we may not see any products based on this standard before 2021. But P-SHINE has researched and developed USB4 cables in advance, please click the link to view: USB4 Thunderbolt 3 Cable