A serial advanced technology attachment dual-in-line memory module (SATA DIMM) assembly includes a SATA DIMM module with a first circuit board, an expansion slot, and an expansion card with a second circuit board. A first edge connector is arranged on a bottom edge of the first circuit board and includes first power pins connected to a control chip and first storage chips, and first ground pins. A second edge connector connected to the expansion slot is arranged on a top edge of the first circuit board and includes second power pins connected to the first power pins, second ground pins, and four first signal pins connected to the control chip. A third edge connector engaged in the expansion slot is arranged on a bottom edge of the second circuit board and includes third power pins and four second signal pins connected to the second storage chips, and third ground pins.