A memory subsystem system including a rectangular printed circuit card having a first side and a second side, a length of between 149.5 and 153.5 millimeters, and first and second ends having a width smaller than the length. The memory system also includes a first plurality of pins on the first side extending along a first edge of the card that extends the length of the card, and a second plurality of pins on the second side extending on the first edge of the card. The memory system further includes a positioning key having it center positioned on the first edge of the card and located between 84.5 and 88.5 millimeters from the first end of the card and located between 62.5 and 66.5 millimeters from the second end of the card.