The Lenovo ThinkPad Carbon X1 3rd Gen Laptop Supports Single Drive Configuration Only. (One M.2 NGFF (2280) Solid State Drive) Note: This machine supports M.2 PCIe NVMe 3.0 x4 Solid State Drives, but the system board only runs at 3.0 x2 speeds. (The M.2 slot supports SATA and PCIe NVMe Solid State Drives)