Don't forget the PCIEx1 card will fit into any free PCIE slot on the motherboard you don't have to use a x1 slot.
No a PCIEX1 will fit into any PCIE slot, a PCIEX4 will fit in any slot X4 size or larger, a PCIEX8 card will fit a PCIEX8 slot or a PCIEX16 slot.etc etc.