Intel apresenta o Thunderbolt 4 combinando o melhor do Thunderbolt 3 e USB4 com conectividade universal e maior segurança

Durante a Computex 2019, a Intel falou sobre a integração das capacidades do Thunderbolt 3 na especificação USB4. Mais tarde naquele ano, a especificação USB4 foi finalizada com o objetivo de diminuir a confusão entre vários tipos de USB e permitir o uso de um conector USB tipo C padrão. Hoje, a Intel está oficialmente retirando o Thunderbolt 4 (TB 4) do padrão. O Thunderbolt 4 será agora a base para o protocolo USB4, ao mesmo tempo em que oferece algumas características adicionais além das especificações USB4 padrão. 

Thunderbolt 4 brings no changes to the total throughput — we still get the same 40 Gb/s bandwidth that Thunderbolt 3 offered. However, the requirements for a device to be certified for Thunderbolt 4 have now changed. For instance, a TB 4 device will now support two 4K displays or one 8K display with a PCIe data throughput at 32 Gb/s. Other requirements include that at least one of the TB 4 ports on the PC should allow for charging and the ports should allow the PC to wake up from standby. TB 4 also uses Intel VT-d for Direct Memory Access (DMA) protection.

Unlike USB4, which offers a choice between 20 Gb/s and 40 Gb/s throughput, TB 4 is always 40 Gb/s and uses a common Type-C connector that allows for all capabilities offered by the protocol including DisplayPort-out and power delivery.

As discussed earlier, TB 4 builds upon TB 3 and offers parity with the USB4 spec. The table below illustrates the differences between the various USB specs available. The additional features offered by TB 4 include the support for 40 Gb/s cables from 0.2 m to 2 m in length. Intel said that it is looking to expand cable length to 5 to 50 m in the future. TB 4 now mandates that the PC or laptop support dual 4K display outputs, PCIe bandwidth of 32 Gb/s (2x that of the requirement of TB 3), and support for VT-d among others.

Intel said that TB 4 can be implemented irrespective of the processor type without any licensing fees, which means upcoming ARM-based Macs as well as future AMD processors are also likely to offer TB 4 support. 

Intel is also introducing a new controller for TB 4. The Intel 8000 series TB 4 controllers include the JHL8540 and JHL8340 host controllers for PC OEMs, and the JHL8440 controller for accessory makers. The new 8000 series TB 4 controllers will make their debut in PCs and accessories later this year starting from the upcoming Tiger Lake laptops including the ones made according to the Project Athena guidelines.

Intel said that a wide range of accessories for TB 4 would be made available starting later this year. All TB 4 docks can offer up to four TB 4 ports. TB 4 now supports a multi-port accessory architecture wherein a single dock will now be able to connect to dual 4K displays, allow for external PCIe SSDs with storage speeds up to 3,000 MB/s and still offer enough bandwidth for connecting additional peripherals. Devices using TB 3 and multiple USB standards can be daisy-chained together in whatever manner the user pleases and all these devices will interface with the PC via a single TB 4 port.