Dual-Port 2.5GBase-T PCIe Network Adapter RTL8125B 2500/1000/100Mbps PCI Express Gigabit Ethernet NIC Card RJ45 LAN Controller

This device is plug and Play when it comes to Windows 10 or higher. I have not tested this device on any Windows operating system prior to Windows 10. This device has been tested on Linux as well and it works perfectly fine and is detected in Linux. I have also tested this on PF sense and open sense and this network card works on both. This network card has also been tested with proxmox virtualization environment system OS and the card is detected as well. I do not believe that you would be able to have one Ethernet Jack go to 1 VM and the second ethernet Jack going to another VM but I can't say for certain as I have not tested it yet. Once I have additional equipment I will be doing additional testing. Please note: I have not been able to fully test the throughput of this device as this is the only device that I have that is a 2.5 gigabit speed. However, based on gigabit speed which is what I currently have in my house, this device performs perfectly on one gigabit speed. Will need to conduct additional testing once I upgrade to 2.5 gigabit speed in order to fully compare and finish this review. Once I have the router /switch that can do 2.5 gigabit speeds. I will update this review with my findings.

Very poor thermal design. The heatsink hits not 1, not 2, but 5 passive components. FIVE. (big yellow cap on the bottom-left, some dip-8 packaged transistor in the top left, and 3 tall SMT resistors) These passive components are taller than the IC that the heatsink is supposed to cool, so the heatsink doesn't sit flat on the actual heat-generating part. I don't know if the original cooling may have been "fine" as I did a small mod to the heatsink and used a taller thermal-pad to sink the main IC. When installed, the NIC worked fine to transfer nearly a terabyte of mixed small and large file data between two Truenas systems.

Used this for TrueNAS core and it works great. You do need to enable the kernel module in tuneables. I have yet to have any issues with the included driver in TrueNAS core and only needed to enable the tuneable which I will include below as I have seen this be asked quite a bit online:Variable = if_re_loadValue = yesType = loaderRunning TrueNAS-13.0-U6

Arrived in time and worked like it stated

After a few months of use, one of the RTL8125 devices randomly vanishes from the PCI device list. Messing around with the heatsink can sometimes fix it for a little while so it's probably a bad solder joint.

There aren't a whole lot of choices when it comes to 2 port RTL8125 cards. I purchased this with the primary intention of using it in my VMWare ESXi 6.7 server. I installed the card, along with the RTL8125 drivers for ESXi (via a custom installer disk I created). At first, both ports on the card were recognized in the ESXi GUI. After a server reboot the ports did not appear, and also I noticed the card was very hot (could hardly grab it to remove it from the system). I replaced it with a single port RTL8125 card which runs much cooler (and I didn't really need two ports anyway).I put this card into a PC and booted both Windows 7 and Windows 10. The Windows 7 which already had drivers for RTL8125, but the card was not recognized as an ethernet controller. There is a (small) CD that came with the card and I installed the driver from that CD but it was the same version that I already had installed from the Realtek website. The card was only recognized as 5 PCI-to-PCI Bridge controllers. I then booted Windows 10, which knows how to automatically install RTL8125 drivers (and I had my single port card already installed and recognized in that system previously) but this card did not get recognized in device manager as an ethernet controller.I believe my card is dead. I'm not sure if it typically is supposed to run very hot.I'll give this two stars because it comes with a low profile bracket and a driver CD, and 2 RTL8125 ports on one card would be nice to have when they work (which they did for a short time)

The dual port card using the shorter PCI-e slot works great in my older Dell PC that is my PFSense router. Had to do the manual reference to the Realtek driver in PFSense but that was easy. Throughput is smoking too.....