Worth it....get it.
Just put it into a Gen 3.0 x 8 PCIe slot and Windows 10 will recognize it and install the driver without issue. It was packed well, in good condition and works great....definately worth it because of the insane pricing of QNAP 10GB card.
If you are new to 10GB, like I am, just be aware of a couple things. My QNAP NAS (TVS-471 )would not boot with it. Fortunately I have a PC, a Server and the NAS, so I picked up 2 other Mellanox Gen 2.0 x 4 SPF+ card and put the CX312C in the server. Win10 and Server16 handled any of these cards, but the NAS is temperamental. Even the Gen 2, though it booted, would not recognize the Mellanox as a Network Interface Card. I have ticket in to QNAP over this. So be prepared for surprises with non windows machines.
The other thing you should know is that if you are not an expert in sharing NIC's on a windows machine, the best approach is to purchase a MicroTik DRS305-1G-$S+IN. Then all you need to do is connect the cards to the 10GB switch and disconnect all Gigabit LAN cards in your machines and then plug the MT into your router via 1GB RJ45. This was an outstanding upgrade with the Mellanox cards.
Verified purchase: YesCondition: Pre-owned