Recently ran iperf3 tests between a Variscite VAR-SOM-MX8X and a Linux workstation through a low-end Netgear switch. I was surprised that we got near 1Gb throughput:
The VAR-SOM-MX8X has two Ethernet ports, so I then ran two tests in parallel and got 1/2 the bandwidth. Ethernet is very well designed to get nearly full bandwidth – must be very little overhead.
Perhaps this is expected as both Ethernet phys are attached to the same MDIO bus.