The Lenovo Slim Pro 9 16IRP8 Laptop Supports Single and Dual Drive Configurations. (Two M.2 NGFF (2280) Solid State Drive) Note: There are two M.2 slots on the system board, M.2 slot-1 (SSD1) supports PCIe Generation 4.0 x4 speeds and slot-2 (SSD2) supports PCIe Generation 3.0 x 4 speeds. M.2 Drives with PCIe Generation 4.0 x4 performance installed in slot-2 (SSD2) are downgraded to closer to PCIe Generation 3.0 x4 performance due to the system board slot limitations.