I haven't seen benchmarks, but my understanding is to officially claim USB4 support with Windows, 40Gbps and PCIe tunneling support are both required. This PC World article has some real world testing w/ a Ryzen 6000 laptop: https://www.pcworld.com/article/703578/usb4-support-amd-ryze...
I'm sure you can get a BSP contract w/ AMD to get implementation details (or simply have a relationship with a board design partner, but I'm not really sure why there would be an expectation for public information on something that's not really relevant to the general public).
I'm sure you can get a BSP contract w/ AMD to get implementation details (or simply have a relationship with a board design partner, but I'm not really sure why there would be an expectation for public information on something that's not really relevant to the general public).