Question - PCIE x8 into a PCIE x4

PCIe vs PCIe : What's the difference? pcie 4 slot By you sticking a UAD-2 card into the second slot, the motherboard detects this and automatically throttles the first slot down to 8x assuming you have stuck in pciex16 slot configuration PCIe boards can fit into slots designed for their lane configuration or higher Plugging a x4 PCIe into a x16 slot is acceptable

pcie slot x16 Slot 2, PCI Express x16 ; Slot 3, Slot not available on this board ; Slot 4, Slot not available on this board ; Slot 5, PCI Express x8 in a