Common mode voltage can be anywhere between 0 and 3.6V, making the transmission of data fairly low power. A full PCI Express link is a collection of one or more symmetric lanes in each direction, and combinations are specified by PCI-SIG in the base specification. A x1 Link consists of 1 Lane or 1 differential signal pair in each direction for a total of 4 signals. A x32 Link consists of 32 Lanes or 32 signal pairs in each direction for a total of 128 signals. Links can be defined as x1, x2, x4, x8, x12, x16 or x32.

