Maximus V gene pcie bifurcation

I recently modded my bios for nvme and got it all setup but I can’t run the nvme drive at full speed because the two 3.0 16x slots are meant to split into two 8x slots for sli. But when I connect the ssd it runs at 4x and so does the gpu. The only other slot a have available is a pcie 2.0 4x. Would pcie bifurcation be the solution if possible or does anyone have any other ideas?

If you have sli setup it will not work even bifurcation. best will be using single gpu setup.