Comment by sparky

The only real similarity to PCIe is that they're both high-speed differential signaling standards. This article has a good overview of what is known: http://www.anandtech.com/show/7900/nvidia-updates-gpu-roadma... .

For an example of what the signaling might look like, see https://research.nvidia.com/publication/054-pjb-20-gbs-groun...