[vardump]

I've tried the same method and it's about 10 Gbps, not 10 GBps.

[ThePowerOfFuet]

Sounds like you were actually using USB 3.1 Gen 2 or USB 3.2 Gen 2[x1], not Thunderbolt 4.

[bhaney]

Thunderbolt 4 can't do 80Gbps either

[vardump]

I tried it with M2 Max Macbooks. Definitely TB4/USB4 capable.

[walterbell]

With a certified TB4 cable?

[vardump]

Yes.