Motherboards even have externally-accessible connections in a rear input/output (I/O) panel that matches into a generally commonplace location on the rear of a case. Today, most GPUs join via PCIe slots, and most use PCIe x16 slots. In addition, most contemporary GPUs require PCIe three.zero or later. The last requirement is the width out there to every PCIe slot, and many GPUs require a width of two slots. This can block some x1 PCIe slots and render them inaccessible, which is okay so long as it doesn’t surprise you. Note that some GPUs can use simply the seventy five watts of power provided by the PCIe slot, but that most GPUs require extra power through six-pin or eight-pin connectors from a large enough energy supply.