Comment by adrian_b

Both 10 Gb/s Ethernet and 10 Gb/s USB have bit data rates that are 3% lower than 10 Gb/s, due to encoding (64/66 bits for Ethernet, 128/132 bits for USB).

So the their maximum speed is approximately 9.7 Gb/s.

Then for Ethernet there is a protocol-dependent overhead, e.c. depending on whether TCP or UDP is used, and depending on whether standard packets or jumbo packets are used.

The TCP overhead can reach in the worst case up to close to another 3%, reducing the achievable TCP throughput to around 9.4 Gb/s.

The USB frames add some extra overhead, but it is normally not important in comparison with other factors that can reduce the throughput.

All that a 20 Gb/s USB port can do is to reduce the overhead of the USB frames, but that is a negligible improvement. Using jumbo Ethernet frames (which are 6 times bigger than standard frames), if both ends support them, is likely more useful for increasing the throughput, than using a 20 Gb/s USB port.