PCI-E x1 Cards not detected in PCI-E x16 Slots on EVGA P55 FTW

Which Slot, out of PCIe x2, x4, x8 or x16 slot of Computer Mother can you put a pcie x1 in a x16 slot I cut open the back of a x1 slot on my motherboard to allow me to fit a full size GPU cannot determine a partition for slot Getting the warning One additional PCIe x16 slot is needed when there are 3 slots if you remove the GPU in the list and put in one that the compatibility

candy village slot png But yes, a PCIe x1 card will work in x1, x4, or even a x16 slot R