The Dell XPS 15 9570 Laptop Supports Single or Dual Drive Configuration Depending on the Battery Installed. (One 2.5" Solid State Drive or Hard Drive with the Smaller 3-cell 56Whr Battery Installed and/or One M.2 NGFF (2280) Solid State Drive) or (One M.2 NGFF (2280) Solid State Drive with the Larger 6-cell 97Whr Battery Installed) Note: Models that have the larger 6-cell 97Whr battery installed do not support 2.5" Drives due to the larger battery occupying the 2.5" Drive bay. If Installing a 2.5" Drive in models with the smaller 3-cell 56Whr battery installed, you will need the 2.5" Drive cage p/n 03FDY3 and rubber rails p/n 03XYT5 and cable p/n 0XDYGX for installation. (The M.2 slot supports SATA and PCIe NVMe Solid State Drives)