PCIE x1 card in PCIE x16 slot?

It allows some flexibility to use cards of one size with slots of another PCIe cards fit in any PCIe slot on a motherboard that is at least as

#1 mistake when installing GPU Graphics Card Video Card cobuman PCI-E Slot

pcie 30 x1 slot Slot 3 Slot Embedded PCI Device 1st in Chassis = 0 Slots = 0 Primary = 0 Proprietary Bus Figure 24-23 : Chassis Example One Secondary 1

pcie 40 in 30 slot Part 1 of 4