Does this Ryzen B450 board support PCIe bifurcation?

[HunterAP]

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.

[OrbitaLinx]

I don’t have experience with this how ever I always thought it was up to the CPU and cable as PCIE on this board should be wired directly to the CPU?? It’s not like this board is running half its x16 slots threw a PCH that might interfere… Why don’t you just use a QUALITY PCIE riser cable for the GPU and free up your 1x, slot problem solved if you can stick your capture card in it?

[gordonthree]

There will be an option for it in the BIOS if it’s supported.

Just to hazard a guess, I’m not super up to speed with the b450 chipset. I do know that my x470 has bifurcation options of x16/x0 or x8/x8, for the ONBOARD slots. The x16 won’t bifurcate externally far as I can tell from what I’ve read.

An ACTIVE riser will do what you want, but a new motherboard might be cheaper.