I have a Beelink SER6 (https://a.co/d/dK6AfIo).

I have a 10 gigabit thunderbolt ethernet card plugged into a 10 gigabit switch. I am only get 5.6 gigabits according to iperf3.

I know that the ethernet dongle on the other end is able to send and receive 10 gigabits as its been independently tested, as has the switch.

I am running Linux on here; boltctl seems to indicate that it should be working:

[tombert@nixos:~]$ boltctl
 ● Sabrent Ethernet Adapter
   ├─ type:          peripheral
   ├─ name:          Ethernet Adapter
   ├─ vendor:        Sabrent
   ├─ uuid:          cf030000-0082-8088-20e4-96c4ce253906
   ├─ generation:    Thunderbolt 3
   ├─ status:        authorized
   │  ├─ domain:     f0833804-c04b-b91b-ffff-ffffffffffff
   │  ├─ rx speed:   20 Gb/s = 2 lanes * 10 Gb/s
   │  ├─ tx speed:   20 Gb/s = 2 lanes * 10 Gb/s
   │  └─ authflags:  none
   ├─ authorized:    Sun 02 Jun 2024 11:26:15 PM UTC
   ├─ connected:     Sun 02 Jun 2024 11:26:14 PM UTC
   └─ stored:        Mon 20 May 2024 04:10:07 PM UTC
      ├─ policy:     auto
      └─ key:        no

I had a hypothesis that not enough lanes are being used by the card, but I don’t see an option in the bios to set that. Any ideas would be helpful/