A stacked I/O connector with surface mountable tails and a printed circuit board (PCB) configured to receive the connector. The connector may avoid terminal deformations or scratches when the connector is mounted to the PCB. The PCB may include solder pads on a single surface or both surfaces. The sold pads may be configured for the tails of the connector to be attached with a surface mount soldering technique. As a result, the connector has high density and high speed, requires, requires a smaller mounting area on a PCB, relaxes the limitations in routing PCB traces, and reduces the electrical performance deterioration caused by PCB trace routing limitations. The connector may have row-oriented terminal subassemblies, holes in the connector housing and other features to facilitate reliable manufacture and operation of the connector.