AFAIK your card can be 1Gb, but you have also to check your ethernet cable. I don't exactly remember the numbers
but if your cable is Cat5 or less, you won't be able to get more than 100Mb. I believe a cable Cat 6A is the minimum
in order to expect 1Gb. Nevertheless, you should be able to get at least 100Mb with your new card whatever the
cable is.

    Patrice Nevertheless, you should be able to get at least 100Mb with your new card whatever the
    cable is.

    I think so.

    • [deleted]

    Try booting the LTS kernel and see if it works there.

      [deleted]

      Done by booting the LTS, same issue.
      Do you know a PCI card 10/100/1000 which could do the job, please ? Thank you very much !

      1. Check your cards inxi -ixx.
      2. See which one is active nmcli -p device.
      3. Disconnect the active card nmcli dev disconnect (your active device)
      4. Try activating the connection of the new ethernet card nmcli dev connect (new card Eth)

        OK, I'm ashamed.
        I did what pomon said: it didn't work. So I decided to check with another Ethernet cable, and guess what ? It worked ! Meaning the issue wasn't my built-in Ethernet card, but the cable. The built-in Ethernet card is able to deliver 1000 Mb, and it does it very well.
        I'm very ashamed, I thank everybody very much, and I apologize for all the inconvenience.
        Solved !

        I don't know why my reply has to me moderated ?

          Here is what I wrote a couple hours ago:

          OK, I'm ashamed.
          I did what pomon said: it didn't work. So I decided to check with another Ethernet cable, and guess what ? It worked ! Meaning the issue wasn't my built-in Ethernet card, but the cable. The built-in Ethernet card is able to deliver 1000 Mb, and it does it very well.
          I'm very ashamed, I thank everybody very much, and I apologize for all the inconvenience.
          Solved !

          Bouquins I don't know why my reply has to me moderated ?

          auto mod thought it was spam for some reason. 🤷‍♂️