The QNAP TS-873A's eight SATA bays pair with Gen 3 x4 NVMe slots

Eight drive bays make the TS-873A a capacity monster, and the two M.2 NVMe Gen 3 x4 slots mean your cache or storage pool has full bandwidth. The x4 lanes per slot is a nice touch — some competitors starve their M.2 slots on larger NAS units. Standard 3.5-inch and 2.5-inch SATA drives fill the main bays.