Some motherboards from earlier models still have it, even though the more modern PCIe slot has largely replaced it. PCIe slots. Different sizes of PCIe slots are available, satta king meinsuch as PCIe x1, PCIe x4, PCIe x8, and PCIe x16. A variety of expansion card types can be installed in these slots; the most popular one for connecting graphics cards is the PCIe x16 slot. PCIe interfaces are perfect for high-performance hardware components because they have higher data transfer rates and more bandwidth than standard PCI slots.