Bifurcation x4 into two times x2

ECC, SDDC , ADDDC (for x4-based memory DIMMs Rear: Up to 10x PCIe slots, plus a slot dedicated to the OCP adapter Slot

The adapter card I am looking at can be used in a X4, X8 or X16 PCIe slot and they say I will get up to 32Gbps when it is plugged into a PCIe

x4d slot Active slot card adapter for up to 4-lanes PCIe Converts standard PCIe slot card format to 80pin ERF8 for PowerTrace Serial Pinout conform to PCI-Express

kumpulan nexus slot The specs table says, 1 x PCIe x16 slot, running at x4 Does this mean this x16 slots header only has 4 PCIe lanes?