A:Answer On Youtube, search for nitro 5 an515-55 ssd upgrade. The first video that popped up for me was the disassembly video. At 2:37, it shows the m.2 slots, one above the 2.5" drive bay, the other next to the memory, marked as 1 and 2. First one can only use an M.2 2280 PCIE NVME, the second can use either an M.2 2280 PCIE NVME or an M.2 2280 SATA. The SATA bay takes a standard 2.5 7MM SATA drive, for a total of three drives. I currently own this laptop, have three drives installed for a total of 10tb.