i7 6700k to i7 6700k... Samsung 960 Pro M.2s (@ 2000-3000Mbps) and Samsung 950 Pro SSDs (@ 500Mbps) on both machines. Surely you can see that a 1G ethernet connection at 120Mbps is a bottleneck.
I'm not sure if it would speed up network rendering in KeyShot. All I know is that data is transferred from the master machine to the slave for rendering, the slave renders its portion of the image and sends it back to the master. I don't know if a 1G connection would inhibit this process, but I do know that network rendering over wifi can slow the process so it would follow that the faster the connection the better. Anyone with any insight on this please chime in.
Regardless of network rendering, transferring files between the two machines via 40G USB-C; which is already on my motherboards, would be much faster and would be cheaper than buying two 10G ethernet cards.
As to your solution: I'm not sure that what seems to be primarily a migration cable would work as a network cable... similar to a crossover cable. My thinking is that KeyShot network rendering wouldn't be compatible with it. 5G is certainly better than IG, but I was hoping for a solution closer to the 40G potential of USB-C.