U.2A hardware interface for connecting SSDs to the computer over the PCI Express (PCIe) bus. Originally known as "SSD Form Factor-8639" (SFF-8639), U.2 is hot swappable and uses the traditional 2.5" and 3.5" drive housings for very large capacity solid state storage but with its own pin configuration. U.2 supports a mix of PCI Express, SATA and SAS drives, and its four PCIe lanes can be configured as a single port or dual port for redundancy. See M.2 and NVMe.
|Put M.2 on a U.2 Form Factor|
|This Ableconn adapter allows an M.2 SSD to fit into a U.2 socket. (Image courtesy of Ableconn Technologies, www.ableconn.com)|