U.2 SSD
prices on 23 models U.2
— a connector specially designed for high-end internal drives in the 2.5 "form factor, mainly for server purposes. Actually, U.2 is the name of a specialized form factor (2.5", 15 mm high), and the connector is formally called SFF- 8639. Such modules are connected in the same way as PCI-E expansion cards (via the same bus), but they are smaller in size and can be hot-swapped. In addition, they are almost guaranteed to support NVMe (see "Advanced") — the U.2 specification was originally created with this technology in mind.