Card running x1 in x16 slot?

Using a PCIe x1 card in a PCIe x16 slot pcie slot x16 if the slot is open like that, you should be good to go if it's not open, you could a) use another riser to adapt the x8 to x16, or b) pcie slot height It's a slot of x16 size but electrically x4 This

pciex1_1 slot A PCIe x8 card will fit in any PCIe x8 or PCIe x16 slot PCIe cards larger than the PCIe slot may fit in the smaller slot but only if it is open