miniSAS uses differential signaling to enable high speed data transmission. In the board mount connector, the bottom row of contacts is identified as the ‘A row’, with the top row referred to as the ‘B row’. Each A pair and B pair has a defined signal or ground function. As shown here, the differential signal pairs A2/B2 and A3/B3 are flanked by ground pairs A1/B1 and A4/B4.