I have done everything I can do from that guide. The BIOS settings are completely different to my servers BIOS, and the mlxconfig command does not return LINK_TYPE_P1 or LINK_TYPE_P2.
I did change the Jumbo packet setting, and doing so increased the speed of my tests to 14419 MB/s (the ntttcp settings recommended in the guide resulted in only 9334 MB/s). But this is still only 1.4GB and nowhere near 10GB.
I am testing the card on a development machine. I need to give the go ahead for my hosting company to purchase x8 of these for my servers as per their recommendation, but I am concerned about doing this while they are underperforming so badly on my kit.
I contacted networking support as you suggested, but they will not deal with me without a contract. I object to paying for support when there is clearly an issue with the Mellanox card/drivers under Windows 10 that is causing this problem.