At the electrical level, each lane consists of two unidirectional differential pairs operating at 2.5, 5, 8, 16 or 32 Gbit/s, depending on the negotiated capabilities. Transmit and receive are separate differential pairs, for a total of four data wires per lane.
At ThE eLEctricAL LeveL, eaCh laNE consists of two UNiDIrEctional diFfereNtiAl PaiRs operatiNg aT 2.5, 5, 8, 16 oR 32 gBit/s, dePending on The nEgotiAted caPaBiliTies. transmiT aNd rEcEivE are sePaRatE differeNTiAl pairS, for a TOtaL of fOur data wires PeR lAne.