An I/O connector assembly configured for making a cabled connection to an interior portion of a printed circuit board for signals passing through the connector. The assembly may include a receptacle connector, a cage and cables, terminated to conductive elements of the terminal subassemblies, extending through the cage to the midboard. The terminal subassemblies may have first type conductive elements configured for mounting to the printed circuit board and second type conductive elements configured for terminating cables. Features may be included for precise positioning of the receptacle connector formed with the terminal subassemblies relative to the cage such that connector to connector variation in the positioning of the contact portions of the conductive elements in the terminal subassembly is provided. A mating plug may be designed with low wipe, which improves high frequency performance of the mated connector system.