I'm confused at this point, are you saying myself and
@jasonwc along with others in this thread are lying when we say we're using these exact optics with mellanox NICs with no issues? Like I said previously, I'm browsing this forum over that exact combination. I wouldn't recommend something for the fun of it with a vague idea that it may work, I recommended it because myself and others here are using the exact same setup without issue. You could have bad fiber, you could have newer or older firmware, your motherboard might not like supplying extra power to the NIC, who knows. but as you've noticed, you're the only one in this thread having these issues. Hopefully the DACs you ordered work as that will at least narrow it down, although it will be hard for me to recreate here to test because as I've said previously, I put the KAIAM in, and it worked, I haven't been able to coax a failure out of it (especially not one as odd as a 4x10gb SerDes transceiver somehow linking up at 1gbps). At that point I would try your NIC in another server or something