alt Hacker NewsOn the general topic of USB to 1000BASE-T (and now 2.5 GBaseT) dongles, for people who care about performance, it's good to know about the distinction between those that are USB devices and those that are PCI-Express devices.
Basically, what do you get if you hotplug it into a laptop running a current linux kernel and do "sudo lsusb -v" vs "sudo lspci -v"?
The ones that are native PCIE devices offer much better performance, up to 2.5 GBASET line rate, and will communicate with the host over the implementation of thunderbolt over USB.
The ones that are USB only might work okay, but there's a reason they're cheap.
Of course a cheaper laptop also won't have any implementation of thunderbolt on it, so that's something to consider as well.
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Realtek RTL8156 (USB 2.5G ethernet) is fast and rock solid, even for server use cases. I’d take it over an i225 any day
I'm guessing if I accidentally got a pci-e one, it wouldn't work in any of the USB ports I would connect it to (as, to my knowledge, I only have USB ports), or do they generally fall back to working as a USB device?
Could you elaborate on why the USB ones are worse?
Per Wikipedia, USB 3.0 (from 2008) can reach 5 Gbit/s, so (naively?) one would expect them to reach 2.5 GbE line rate easily, right?