Intel has published the first brushstrokes of the next generation of Thunderbolt, a new generation of high-speed interface developed jointly by Intel and Apple, which from 2018 can be implemented by any manufacturer without paying license fees.

VESA released DisplayPort 2.1 on Monday and USB-IF released the USB4 2.0 specification yesterday. These announcements highlighted the significant engineering efforts the industry has made to create a a unified protocol capable of handling the enormous bandwidth demands of external I/O computer systems of the future.

The next generation of Thunderbolt

Intel’s new interface has a lot in common with the other two introduced this week. If the aim of the DisplayPort update is to improve integration with USB4, The Intel connector is directly based on USB4 v2. Like it, it works with the multi-protocol tunneling architecture introduced in USB4, which allows doubling the available bandwidth up to 80 Gbps while maintaining the same port, pin and cable design.

To understand the 120 Gbps that Intel is quoting (and which we’ll also get in USB4 V2), it’s necessary to explain that the USB4 connection uses two high-speed differential signaling pairs connected to transmit and receive data, allowing for full-duplex 40 Gbps operation (40 Gbps transmit and 40 Gbps receive) in the symmetrical case. However, the lane initialization process can optionally configure the link to have 3 transmitters and a receiver on one side and 3 receivers and a transmitter on the other side.

Combined with the higher data rates due to PAM3, this allows the host to send up to 120 Gbps. Even if the receive bandwidth is reduced to 40 Gb/s, there are peripherals that will be able to use it, such as high-resolution displays, which may sacrifice the available transmit-side bandwidth for other purposes (such as high-speed storage).

The upcoming Thunderbolt takes the USB4 2.0 specification as its base and makes all optional features mandatory. Addition, Integrating Intel’s Thunderbolt into notebook processors ensures the energy efficiency of the host-side implementation. Making Thunderbolt mandatory for Intel Evo and vPro notebooks will cement Intel’s leadership in USB.

The dynamic bandwidth balancing feature, which allows tunneling of DisplayPort 2.1 streams while allowing the use of high-bandwidth peripherals, is one of the most interesting features of USB4 v2. And it will certainly be available on systems equipped with next-generation Thunderbolt ports.

In the demo, Intel did not specify the power delivery limits (Thunderbolt 3/4 supports up to 15 W by default) for the next generation Thunderbolt ports. Nor did it provide any information related to market availability, certainly in 2023. Screens, expansion bases, external graphics… There is a wide field of uses to explore. And hopefully finally interface/connector that delivers the promised enormous performance with a single cable.