The Asus G750JH Laptop Supports 1, 2 or 3 Drive Configurations. (One or Two 2.5" Solid State Drives or Hard Drives) or (One 2.5" Solid State Drive or Hard Drive and/or One or Two M.2 NGFF (2260) Solid State Drives using a Dual Drive Daughter Board Installed in the second 2.5" Drive Bay) Note: There are two 2.5" Drive bays in this machine. The M.2 Drives use a daughter board p/n 90NB0181-R10040 in replace of the second 2.5" Drive. If adding the second 2.5" Drive, you will need the 2.5" Drive caddy p/n 13GNY81AM020-2 for installation.