The Lenovo ThinkPad X1 Extreme 4th Generation Laptop Supports Single or Dual Drive Configurations depending on the Graphics Card Installed. (One M.2 (2280) SSD Slot with the NVIDIA GeForce RTX 3060/3070/3080 Graphics Card) or (Two M.2 (2280) SSD Slots with the Intel UHD Graphics or NVIDIA GeForce RTX 3050 Ti Graphics Card) Note: M.2 slot 1 (slot A NVMe0) supports Generation 4.0 x4 and 3.0 x4 speeds and M.2 slot 2 (slot B NVMe1) supports Generation 3.0 x4 speeds. M.2 Drives with PCIe NVMe Generation 4.0 x4 speeds are downgraded to closer to Generation 3.0 x4 speeds in M.2 slot 2 (slot B NVMe1). This machine supports RAID 0/1 configurations.