What happens if a network card is bottlenecked by PCIe?
Depends on driver … either starts throttling using flow control … or simply drops frames.
Is there a list somewhere?
I don’t think there is.
Do any routers/switches apply flow control when they detect packet loss?
It is not only 50G on TB3 the problem, but 40G+4K should also get bottlenecked by 26G data bandwidth.
I think 40G on PCIe 3.0 x4/TB3 should get bottlenecked with jumbo frames too by 32G data bandwidth. One should also get a bottleneck by default when reading from a true 40G NAS (large frames).
TB3 is 40G but with only up to 32G of PCIe data.