The standard organization USB-IF has recently announced it’s planning to cancel the USB 3.0/3.1 naming. The USB 3.0 has already changed its name to USB 3.2 Gen 1 (5Gbps), the USB 3.1 has been renamed to USB 3.2 Gen 2 (10Gbps), and the USB 3.2 has been changed to USB 3.2 Gen 2×2 (20Gbps). But probably you won’t pay much attention to these names, because today, USB-IF officially announced the USB 4. Note that it is not USB 4.0, it is USB 4.
In terms of transmission rate, USB 4 has doubled its peak transfer speed compared to USB 3.2, reaching 40Gbps (dual-channel). Is it familiar? That’s right, Intel’s Thunderbolt 3 interface is 40Gbps, but the earliest applications were put back in 2015.
To put it simply, USB 4 is equivalent to the current Thunderbolt 3. After all, Intel has announced that it will be open to the public and will be exempt from licensing fees. Starting from 10nm Ice Lake, it will integrate support for Thunderbolt 3 at the processor level. Of course, it is much more open than Thunderbolt 3, because the use of Thunderbolt 3 must be strictly certified by Intel (only 463 models so far).
For other parameters, the USB 4 support up to 100W of power, an external graphics card, two 4K displays or a single 5K display. In addition, unlike the USB 3.0/3.1/3.2 era, which uses the color interface for intergenerational differentiation, USB 4 does not have this requirement. This new interface introduces a new underlying protocol but is also compatible with existing USB 3.2, USB 2.0, and Thunderbolt 3. The physical connector of this standard will be identical to the USB-C of the Thunderbolt 3, which means that all existing Thunderbolt 3 cables should be compatible.
At present, the entire version of the USB 4 standard is still being revised. It is expected that the original version will be released in the second half of this year. So it will take another year for large-scale application.