The USB Implementers Forum has officially published the USB4 specification, a major update to deliver the next-generation USB architecture that complements and builds upon the existing USB 3.2 and USB 2.0 architectures.
The USB4 architecture is based on the Thunderbolt protocol specification recently contributed by Intel Corporation to the USB Promoter Group. It doubles the maximum aggregate bandwidth of USB and enables multiple simultaneous data and display protocols.
USB4 will be capable of delivering up to 100W of power and can be used with external graphics cards as well. It can also power two 4K displays or a single 5K display without breaking a sweat. It is important to use cables that are capable of 40 Gbps speeds for taking advantage of the complete potential of this technology. However, older Thunderbolt 3 cables and accessories will work just fine with the new port.
Key characteristics of the USB4 solution include:
- Two-lane operation using existing USB Type-C® cables and up to 40Gbps operation over 40Gbps certified cables
- Multiple data and display protocols that efficiently share the maximum aggregate bandwidth
- Backward compatibility with USB 3.2, USB 2.0 and Thunderbolt 3
As the USB Type-C connector has evolved into the role as the external display port of many host products, the USB4 specification provides the host the ability to optimally scale allocations for display data flow.
Even as the USB4 specification introduces a new underlyingprotocol, compatibility with existing USB 3.2, USB 2.0 and Thunderbolt 3 hosts and devices is supported; the resulting connection scales to the best mutual capability of the devices being connected.
The upcoming USB Developer Days 2019 will include detailed technical training covering the USB4 specification and the latest for USB Type-C, USB Power Delivery, and new USB-IF branding strategies.