The USB Promoters group within the USB-IF has announced that the final specifications for USB4 will be published later this year. Based on Thunderbolt 3, USB4 will offer 40Gbps throughput using the USB-C connector. Unlike Thunderbolt 3 however, it will be royalty free. This has been a long term goal of Intel, the company behind the Thunderbolt protocol.
The new USB4 architecture defines a method to share a single high-speed link with multiple end device types dynamically that best serves the transfer of data by type and application. As the USB Type-CTMconnector 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 underlying protocol, 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.USB Promoters Group
Today, Thunderbolt is a license technology and expensive. This is why it is not widely seen in the PC world. Apple standardized on it several years ago. With this new standard being royalty free and providing the same speeds as Thunderbolt, high speed peripheral connectivity will be far less expensive and more widely available.
While the specification is yet to be written, here is what is known about USB4:
- Two-lane operation using existing USB Type-C cables and up to 40 Gbps operation over 40 Gbps-certified cables
- Multiple data and display protocols to efficiently share the total available bandwidth over the bus
- Backward compatibility with USB 3.2, USB 2.0 and Thunderbolt 3
The USB Promoters group indicated in their press release that 50 companies, including Apple, are working on the standard.
While the standard for USB4 will be coming out this year, don’t expect to see it on any Mac or PC. It is likely to take another year or more before it becomes standard on your laptop.