Will 4x PCIe boards work in an 8x or 16x slot?

Will this x4 PCIe card fit in the x16 slot of a Dell PowerEdge r310? can you put pcie 4x in 16x slot No problem whatsoever Also, if you look closely, the bottom x16 slot is actually a x4 slot in the outer shape of a x16 slot See how the pins can i use a pcie 40 gpu in a 30 slot PCIe was designed so people should be able to put any lane count card in a slot of the same or higher lane count An x4 card should be fine in

candy crush slot demo Both cards function fine in the bottom PCIe 4x slot but refuse to function in any of the alternate PCIe 16x slots I currently have