The Dell Alienware x17 R1 Laptop Supports Single and Dual Drive Configurations. (Two M.2 NGFF (2280) or (2230) Solid State Drives) Note: The M.2 (2280) and (2230) Drives each use a unique thermal shield and cannot be interchanged. The M.2 (2230) Drive uses thermal shield p/n 0XR11G and the M.2 (2280) Drive uses thermal shield p/n 0C99KM. The M.2 (2230) Drive uses a adapter bracket p/n 0R88X3 to accommodate for both of the larger M.2 (2280) slots. (M.2 slot 1 (SSD-1) supports Generation 4.0 x4 and 3.0 x4 NVMe performance and M.2 slot 2 (SSD-2) supports Generation 3.0 x4 NVMe performance only)