Looking for a cheap mobo/CPU/RAM that support PCI bifurcation for a project - quite happy with second hand suggestions for rackmount servers ect.
have you tried googling it?
You can purchase any of the Asrock X399 motherboards for bifurcation 16 dedicated lanes in 4x4x4x4x configuration. Also Asus X399 motherboards supports bifurcation with their latest bioses.