As others have said, the card also has to be PCIe 4.0. On the used market, I mostly see PCIe 2.0, which means they need quite a lot of lanes. There's also the

As others have said, the card also has to be PCIe 4.0. On the used market, I mostly see PCIe 2.0, which means they need quite a lot of lanes. There's also the fact that people usually use "older" components to build home servers, and if I'm not mistaken, PCIe 4.0 is only supported in fairly recent CPUs, and with not that many lanes; whereas my desktop from circa 2012 comes with something like 40 PCIe 3.0 lanes.