10Gtek 10Gb PCI-E NIC Network Card, Dual SFP+ Port, with Intel 82599ES Controller, PCI Express Ethernet LAN Adapter Support Windows Server/Linux/VMware, Compare to Intel X520-DA2(E10G42BTDA)

This card is easy and powerful. It comes with a PC case bracket and a server-style bracket which fit my HYTE case perfectly. One hurdle is the Win11 driver install, and since I have 2 ports, I had to install the driver for both of them. Use the Device Manager "update driver" process. I assume if you are buying this level of hardware, you have some idea of what you are doing... Download the Intel Win10 family drivers, I'd go for the complete set option. After extraction, find the PROXGB>Winx64>NDI565 folder, hit enter. Yes, the NDI565 folder (completely non-intuitive, I know...). Viola NIC recognized, do this for all ports in the DM. Happy networking.

Plug-and-play with FreeBSD-based systems: toss it in and the Intel driver just works. As an Intel card, you are limited to Intel-compatible SFP+ modules unless you activate a kernel-parameter override. The card comes with a half-height PCIe slot backer preinstalled; you'll need to swap it with the included full-height backer to use in a standard PC. It runs a bit hot, and works best with a fan blowing on it, but I've had one running for some time with no issues.

I got this to take the place of a Broadcom 2xSFP+ card that liked to have LACP timing fights with my TP-Link equipment and would refuse to establish links on TwinDac cables. I’ve had no issues on Proxmox 9 worked out of the box except for setting up OVS to use the new X520 card. I do not have fiber modules to test but twindac cables work fine for me on this x520.

On Linux, the driver intermittently fails to initialize the connection. No driver updates are expected.

I apparently got a few cards from a bad batch and didn't realize the problem until after the return window. Seller reached out to me. We ran some tests and I sent them back. They then expedited replacement cards to me. Well today I got them setup in my HA cluster. I'm showing nearly identical speeds and latency compared to Intel branded cards. Very happy with the end result here! 10Gtek could have just ignored my previous complaint but instead they went above and beyond to make it right. I operate a production company that happens to make the base product for a final product also sold on Amazon. I've learned something today. I'll be pushing my marketing team to follow up on any bad reviews I get from now on. This is how business is done right. Mistakes and bad batches happen, it's how you handle it that makes a company good or bad. 10Gtek went from an unhappy customer to a future repeat order customer for my 10G needs.

Perfect! Simple process in a Windows machine. Works as advertised. I was a little hesitant as I hadn't really heard of 10Gtek, then I realized basically all the cards are using Intel, Mellanox, etc. chips. I tried a different vendor first, and it was a total failure. This card got link light on my switch immediately, and was a 2 min driver install to get 100% working. I would absolutely by another 10Gtek card.

Works great, popped it in and it came right up on start-up and has been solid.

Worked great for a dual 10G connection from my server to a UniFi switch. True plug-and-play on my Linux build. Much more affordable than the local retail options and the build quality is top-notch. Highly recommend for any home lab or server upgrade.