3 Drive Options in the Dell OptiPlex 7060 SFF
One M.2 2280 slot This slot supports either NVMe or SATA SSDs, so you can install a fast boot drive.
Two 2.5-inch SATA drive bays These bays let you add two cheap SSDs or hard drives for extra storage.
Two additional SATA ports on the motherboard You can use these ports to connect more drives, but the case only has room for two 2.5-inch drives. For redundancy, pair two SSDs in RAID.