An electrical connector includes an insulative housing defining a receiving space (110), a number of contacts retained in the insulative housing, a cable (6) electrically connected with the contacts, and a shielding member (5) enclosing on the insulative housing to form a cavity (120). The contacts comprise a set of first contacts (2) and a set of second contacts (3), each of the first and second contacts having a contacting portion and a tail portion. The cavity has a smaller length than the receiving space along a transverse direction, the cavity is stacked on one side of the receiving space along an up-to-down direction, the cavity has a lateral boundary coplanar with the receiving space, the second contacts are received in the receiving space, and the first contacts are retained in the cavity for transmitting high speed signal.