I want to interface two processing boards with PCI express x8 and connect them with cables. I find 68-pin off-board connectors for x8 connection (by molex) where as there're 98 pins for edge connectors. How do I match these 98 to 68? Are there some documents talking about this? I read PCI Express Card Electromechanical Specification, but there's only edge connector definition inside. Is this 68-pin connector also standard?