Yes, you can install a 1x PCIe card into a 16x or 4x PCIe slot

Running x16 gpu in x1 slot - Hardware Hub pcie 1x slot PCIe slots are used to connect graphics cards, sound cards, other interface cards and some pcie 30 x1 slot Yes any pcie xanything card will work in a x16 slot, i have a pcie x1 asus xonar stx in a 16x slot right now x4 and x8 cards will also work in

pcie x32 slot ✓ Mini PCIe to 3 PCIe 1x adapter expands 3 PCI express 1x slot via your motherboard with mini PCIe can use 3pcs PCI express card (Sound Card , Network