PCI-E x1, x2, x4, x8, x16. Along with that, there's multiple versions of the PCI-E bus, like PCI-E 2.0, PCI-E 3.0 etc.
Four different Sizes
4 different sizes
FOUR
PCI Express currently comes in four different slot sizes; the longest size (PCI Express x16) and the shortest size (PCI Express x1) There are also The accelerated Graphics Port (AGP) and also...