A system includes a housing and a first circuit board positioned inside the housing. The housing has top, bottom, left side, right side, front, and rear panels. The first circuit board has a length, a width, and a thickness, and the first circuit board has a first surface defined by the length and the width. The first surface of the first circuit board is substantially parallel to the front panel or at a second angle relative to the front panel in which the second angle is less than 60°. The system includes a first data processing module and a first optical interconnect module both electrically coupled to the first circuit board. The optical interconnect module is configured to receive first optical signals from a first optical link, convert the first optical signals to first electrical signals, and transmit the first electrical signals to the first data processing module.