USB-IF Announces Publication of New USB4 Specification

What They Say

The USB-IF said a few weeks ago that it would introduce a new USB4 V2.0 to double the speed of the interface to 80Gbps using existing hardware, but with few details. Now it says that it has published the specification. The USB Type-C and USB Power Delivery (USB PD) specifications have also been updated to support this.

Key characteristics of the updated USB 80Gbps solution include:

  • Up to 80Gbps operation, utilizing a new physical layer architecture based on PAM3 signal encoding, over existing 40Gbps USB Type-C passive cables and newly defined 80Gbps USB Type-C active cables.
    • Optionally for certain applications, such as driving very-high performance USB4-based displays, the USB Type-C signal interface can be configured asymmetrically to deliver up to 120Gbps in one direction while retaining 40Gbps in the other direction.
  • Updates to data and display protocols to better use the increase in available bandwidth
    • USB data architecture updates now enable Enhanced SuperSpeed USB data tunneling to exceed 20Gbps.
    • Aligns with DisplayPort™ Revision 2.1 and PCI Express® Revision 4.
  • Backward compatibility with all previous versions of USB.

What We Think

There is a lot to dig into with this and the DP V2.1 announcement so expect more in the coming days. (BR)

USB 80Gbps Branding Overview