ConnectX-4 Lx on FreeBSD on AMD Epyc platform


I have two identical servers:

Platform: Gigabyte R282-Z92

CPU: 2 x AMD Epyc 7282

Memory: 2TB

Drives: 24 x Micron 9300 MAX NVMe

System drive: 1 x WDC SN720 M.2

Network: 2 x MCX4121A-ACAT

System is set to UEFI (also on MCX card I have enabled UEFI_HII_EN and EXP_ROM_UEFI_x86_ENABLE). On first system I have installed VMware ESXi 6.7 and everything is working, all network cards are visible. On second system I have installed FreeBSD 12.1 and have problem with activating Mellanox interfaces.

I’m able to use MFT utils on FreeBSD, flash newer firmware, fetch config/information, set parameters, but loading mlx5en module returns only errors and no any Mellanox interface appears when checking with ifconfig.

Here is output from module load:

Attached also logs from tools.

Any ideas how to start these interfaces?



dmesg.txt (35.3 KB)

mlxfwmanager.txt (1.07 KB)

kldstat.txt (581 Bytes)

mlxconfig_q.txt (16 KB)

Hi ,

For FreeBSD 12 please install the MLNX_OFED driver 3.5

For further information, please refer to :



Hi Artur,

In case the issue persist, please open a support case at




I am facing similliar problem using:

Lenovo SR655

AMD Epyc 7702

Mellanox MT27710 connected via OCP3

I tested using FreeBSD-13-CURRENT including the Mellanox 3.5.2 driver.


AMD Epyc 7502

Mellanox Connect-X 4 Lx (OCP2)

@Flinta @Dominik Zajac

Have you tried enabling x2APIC in server BIOS?