The Intel Server Board S1200V3RPS supports four expansion add-in PCI Express* (PCIe*) slots at most:
Slot 7: PCI Express* Gen2 x1 electrical with x8 physical connector, from PCH Slot 6: PCI Express* Gen3 x8 electrical with x16 physical connector, from processor Slot 5: PCI Express* Gen2 x8 or x4 electrical with x8 physical connector, from processor Slot 4: PCI Express* Gen2 x4 electrical with x8 physical connector, from PCH