Can I Connect a x4 PCIe board into an x16 PCIe Slot?

Updated Apr 19, 2024

Issue Details

I have a x4 PCIe board and I would like to connect it to my computer, nevertheless my computer just has a x16 PCIe slot available. Is it possible use this slot?

Solution

PCIe boards can fit into slots designed for their lane configuration or higher. Plugging a x4 PCIe into a x16 slot (up-plugging) is acceptable. The opposite (down-plugging) is not physically supported.

Up-plugging is physically possible although depending on manufacturer it may cause bandwidth degradation. Slot/Board Compatibility is shown in the next table: