I have the Asus TUF B450M-Plus Gaming mATX board, which has an x16 slot (BGPU), an x1 slot (blocked by GPU heatsink), and an x4 slot (used for a capture card).
I want to bifurcate the x16 slot into two x8 slots so I can put in my x4 10GBe network card.
Can’t find any mention of bifurcation in the manual specifically, but I found an Anandtech article claiming that B450 boards support bifurcation: https://www.anandtech.com/show/13091/analyzing-b450-for-amd-ryzen-a-quick-look-at-all-the-motherboards
While the specifications on the surface make the B450 seem like a carbon copy of the B350 chipset, as they share native support for the same USB configuration, the same SATA configuration, support for a single M.2 PCIe 3.0 x4/SATA port, and six PCI lanes dedicated to PCIe 2.0 slots. They also both enable support for the same PCIe 3.0 bifurcation, giving a single PCIe 3.0 x16 slot, focusing these systems on a single GPU.
Is there any way to find this out definitively without getting a PCIe splitter cable? Preferably either proof that it works for someone else, or even a Linux program / command that can tell me that info would be perfect.