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

pcie x1 slot   Dan pcie 20 x1 slot

Overview Description The PCI-E expansion riser card adapter is designed to convert 1 PCI-E 1X slot into 3 PCI-E 1X slots The 3 PCI-E 1X slots

Motherboard with blue PCI-express slot, close-up and selective focusing An x1 slot is very short, while an x16 slot is comparatively long  Magewell PCIe cards use PCIe interfaces and above Computer motherboard may have PCIe slots compatible with x1, x4, x8 and x16

book of doom slot Install a low profile video card into a system with only a x1 PCIe slot • Install x4 or larger PCIe cards into a system with only x1 PCIe slots available  Helpful Tip: Keep in mind that an SSD is only compatible with a motherboard that supports a slot PCIe buses can support 1x, 4x, 8x, and 16x lanes