Ok, so even if the AMD chips are equal to or faster, Nvidia still has a large advantage with their networking using their proprietary NVLink switching that was most certainly borne from the Mellanox Infiniband IP acquisition. AMD is going to have to rely on more traditional PCI-E based networking for all off-system traffic via Infiniband or Converged Ethernet vs the more optimized Nvidia GPU clustering that uses it's on proprietary super-low latency NVLink-based switching.

https://www.nvidia.com/en-us/data-center/nvlink/

I'm super curious to see how their networking results compare between transports when real testing results between large supercomputer-ish farms get out there.