Intel has revealed more details about the upcoming Thunderbolt 4 connectivity standard, included increased minimum performance requirements, expanded capabilities, and USB4 spec compliance.
As a quick refresher, Thunderbolt is Intel’s alternative to USB, supporting video, data, and power over a single connection. Physically, Thunderbolt 4 will continue to use a USB-C connector, differentiated from standard USB ports by the use of the Thunderbolt logo. Oddly, this will make them indistinguishable from Thunderbolt 3 ports; only Thunderbolt 4 cables will have a number 4 to indicated their compatibility level.
While the bandwidth capabilities have not changed (the 40Gb/s figure from Thunderbolt 3 remains the same), Intel is implementing minimum performance requirements that all Thunderbolt 4 devices must meet in order to be certified. Importantly, Thunderbolt 4 is fully compliant with the upcoming USB4 specification, and it’s also backwards compatible with all Thunderbolt and USB standards.
The video and data requirements have both doubled, and Thunderbolt 4 devices will thus support two 4K displays (or one 8K) and transfer speeds of up to 3GB/s via PCIe 32Gbps (up from 16Gbps). Thunderbolt Networking also continues to be a requirement.
On the power front, the minimum PC port power for accessories remains at 15W (double USB4), but new requirements mean that Thunderbolt 4 PCs that require less than 100W to charge must offer recharging over at least one port, and they must also support the ability to wake from sleep by touching the keyboard or mouse when a Thunderbolt dock is connected.
For the first time, Thunderbolt 4 will offer docks with up to four Thunderbolt ports and universal cables up to 2 meters in length.
Thunderbolt 4 is set to launch this year. Intel will be making the JHL8540 and JHL8340 host controllers available to computer manufacturers, while accessory manufacturers will want the JHL8440 device controller. Additionally, Intel’s own upcoming Tiger Lake processors will be the first to integrate Thunderbolt 4 directly onto the silicon, and Intel also expects Tiger Lake laptops to launch later this year, including Project Athena models.
In the video above, you can see the coming together of all these new announcements, as an Intel representative has a Tiger Lake laptop connected to a Thunderbolt 4 dock with four ports. The single upstream port is used to charge the laptop, while the three downstream ports mean files can be transferred to a Thunderbolt 4 SSD at ~3GB/s all while the dock continues to drive two 4K displays.
More information is available in the official announcement.