Today, USB-C supports various data transfer rates, from 0,48 Gbps (USB 2.0) up to 40 Gbps (USB4, Thunderbolt 3 and Thunderbolt 4). Things are about to change, as today the USB Implementers Forum (USB-IF) he published the USB4 Version 2.0 specifications.
According to USB-IF it will support two-way bandwidth speeds of 80 Gbps, as well as the optional ability to send or receive data up to 120 Gbps.
USB-IF first reported USB4 2.0 in September, saying it would support a data transfer rate of up to 80 Gbps in each direction (40 Gbps per lane, four lanes total), thanks to a new physical layer architecture (PHY – physical layer architecture) based on PAM-3 signal coding.
Intel also introduced Thunderbolt at 80 Gbps, but has yet to release its official specifications.
The USB4 2.0 version appears to be much faster than its USB4 predecessor, which had optional support for 40 Gbps operation.
You'll just have to make sure you check the specs to know what kind of performance to expect.
Once the new USB4 version 2.0 products are released, you'll be able to get 80Gbps with passive USB-C cables that currently run at 40Gbps, but you'll need to buy a new cable if you want to get to 80Gbps+.