Intel x520 based on 82599 chip - performance issues

Hi!

I’ve got small server based on ZimaOS+v1.5.4 equipped with Intel N100 CPU and 16GB RAM. Recently I’ve installed Intel 82599 based X520 SFP+ network card. Unfortunately, even after manually changed MTU to 9000, I cannot get more than ~4Gbit/s.

Eth1 config and iperf3 results below.

May I get your advice on that?


Ayot