pci slotThe top slot on your motherboard will typically be the best place to mount your graphics card, as this is most often the slot that runs at the full 16x speed.PCIe slots come in a variety of physically different sizes referred to by the maximum lane count they support, ie. x1, x2, x4, x8, x16, and x32. A PCIe card will fit into a slot of its size or bger,