there is no PCI-e through USB though, other than Thunderbolt/USB4 or is there?
so if you only have USB ports and care about performance the bigger distinction would be if the USB ethernet device implements CDC-NCM or just CDC-ECM, with the distinction being that CDC-ECM sends the frames to the driver one-by-one and the driver has to acknowledge and process them one-by-one which generates ton of CPU work, while the newer CDC-NCM protocol sends frames in batches...,
on my laptop I can still get full gigabit speeds with a 1Gbit ECM dongle but when I do it uses 100% of one CPU core, while a 1Gbit NCM dongle has negligible CPU usage...
so if you only have USB ports and care about performance the bigger distinction would be if the USB ethernet device implements CDC-NCM or just CDC-ECM, with the distinction being that CDC-ECM sends the frames to the driver one-by-one and the driver has to acknowledge and process them one-by-one which generates ton of CPU work, while the newer CDC-NCM protocol sends frames in batches...,
on my laptop I can still get full gigabit speeds with a 1Gbit ECM dongle but when I do it uses 100% of one CPU core, while a 1Gbit NCM dongle has negligible CPU usage...