Mellanox ConnectX-4 Lx EN Network Adapter (MCX4121A-ACAT)

Installation literally couldn't be simpler. I popped one of these into a PowerEdge R340 and another into an R720xd with zero fussing from either machine's BIOS (but if you're still cheaping-out by not buying the sliding rails, stop that. Go buy the rails with this, so that you can install them while you have that honking beast pulled out. Then, at least next time, you can enjoy the benefits of civilized rack life). Debian and BSD bare-metal recognized this card immediately. No driver install or configuration of any sort was required. It was 100% automatic*. Next, I popped in a couple of Cisco-branded 10Gbps fiber transceivers and some LX cable and they were chatting like old friends. Benchmarks between servers on the same network chatting via a Cisco 3850 (one having a trunk interface, the other an "access"-type) showed transfer rates getting very close to 10Gbps. I think it was 9.8-something Gbps. Very nice! I'm aware that procedure probably sounds really difficult to the average person. But I assume that if you're spending a portion of the precious time you have left on Earth reading reviews on a Mellanox card, you're quite far from average in more ways than one! It's ok, man. You're among family here. We understand. Now stop stressing, buy the card, and be happy. * OK, I'm lying, you do of course have to configure the network address and all of that on the interface, but I'm ASSuMEing that you know that to be true of any card you get.

Card came with incompatible firmware. Packaging looked new or possibly refurbished, however on two systems (Win 11, and RHEL 9) the card was getting only 1 GbE link. I had to manually find the driver on NVidia's website and download the correct firmware and burn it to the card using their terminal utility. The firmware that was on the card was a version that was not documented as released or in beta, NVidia provided feedback that it is highly suspicious.

I installed it in a RHEL 7 system and it drivers detected the card without any issues.

Great inexpensive 2x 10/25 card for server needs. Using with dual DAC cables, works reliably in a 24/7 environment.

Right now the best buy on the market for 10/25G card. I found the 10G performance to be about 10% faster then equivalent Intel card and 25G performance was even better. My go to card.