> they will go with three different scale-up switch solutions over the lifecycle of Trainium3, starting with a 160 lane, 20 port PCIe switch for fast time to market due to the limited availability today of high lane & port count PCIe switches, later switching to 320 Lane PCIe switches and ultimately a larger UALink to pivot towards best performance.

It doesn't have a lot of ports and certainly not enough NTB to be useful as a switch, but man, wild to me than an AMD Epyc core has 128 lanes of PCIe and that switch chips are struggling to match even a basic server's worth of net bandwidth.