Im gonna buy one of that things.
I have two question related.
This works in manjaro “from the box”? if not, is better to buy some brand/model in particular?
And about the bandwith. Somebody know what is the real bandwith from this devices? i mean because they say ethernet 100MB/s but… USB is capable of that? Because i have wifi but im thinking on put this pc to work as server so it will be better if have better connection than wifi.
Generally yes, but check on the description if Linux is supported.
Note that USB 2.0 supports 480 Mbit. Most of this bandwidth is shared, so 240 Mbit per port if 2 ports are connected to same internal hub. That is then round about ~30Mbyte/s. So yes, it can have a bandwidth of 100Mbit.
That depends on the chipset used in the device.
Provide hardware info of that device by checking the technical info, or at least provide the exact Brand+Model of that device so others can search it on the internet.
The reason is there are many different USB-Ethernet devices on the market and they all use different chipsets.
The chipset is important for the driver to be used, not all chipsets are supported on Linux.