What's the bandwidth and form factor for PCIe x1 x4 x8 and x16?

Yes, you can install a 1x PCIe card into a 16x or 4x PCIe slot x1 pcie slot Dell XPS 8700 comes with a one PCIe x4 slot on the systemboard You can refer to picture below for it x1 slot On the other hand, it provides multiple additional slots for adding more cards to Connect with your motherboard In most cases, it is used in the PCIe x1 slot,

x16pciexp slot PCIe x1: These are the smallest PCIe slots, used for almost any other cards like average network adapters and USB expansion cards PCIe x4: