At the moment it is difficult to clarify what exactly which USB port is capable of. The different standards are confusing and can be subdivided into different versions, which can differ from each other depending on the manufacturer of the respective device. USB 4.0 should put an end to this. It will be an improved version of Thunderbolt 3.
Today it is not always clear what is behind a USB-C port. In case of doubt, the port can only establish a USB connection. But even then the question still arises whether the standard 2.0, 3.0 or 3.1 should be used.
Many USB-C ports are also equipped with so-called “Alternate Modes”. You can also transmit DisplayPort, HDMI or MHL. If the connection is to a device with an Intel CPU, Thunderbolt can also be used as the protocol behind the connection.
So USB-C is by no means the same as USB-C. It’s hard for the end user to see exactly what’s behind the USB port, and the different protocols that can be behind the port can be quite different.
USB 4.0 is more or less Thunderbolt 3
The new version 4.0 should now end this chaos. From this version on USB will be completely based on Thunderbolt. In plain language, this means that users with a USB-C port will receive a Thunderbolt port in the future. As a side effect, Thunderbolt will be royalty-free, which could help this protocol achieve its final breakthrough.
New USB-C ports are thus unified. They offer everything that Thunderbolt offers – namely a Thunderbolt transmission speed of 40 Gbit per second, DisplayPort 1.2 or 1.4 and an electrical output of up to 100 watts. Thunderbolt 3 also offers a USB 3.2 transfer rate of 10 Gbps – which the new USB C port will outperform at 40 Gbps.
Furthermore, the annexation is intended to support several other protocols, although it is not clear which they will be. However, it can be assumed that this refers to the previous “Alternate Modes”.
Strictly speaking, USB 4.0 is an improved version of Thunderbolt 3 and will eliminate the difference between the two protocols.