I am currently laying out a space constrained PCB which contains some USB 3.0 Superspeed differential pairs. These USB signals are confined to the PCB, going from a Cypress CX3 chip to a USB 3.0 Hub chip. They do not go to or come from a connector. The signals are approximately 30mm long from start to end.
According to the advice, the Superspeed pairs should be separated from each other by at least 5x the differential pair spacing. (This is known as the 5W rule)
Since the signals are fairly short, and do not go through a connector or cable, would it be possible to push them a little closer than 5W? Say, 4W or 3W?