A SAS HBA is a type of Small Computer System Interface (SCSI) HBA, but the term SCSI HBA is no longer in widespread use. A SCSI HBA typically is associated with parallel SCSI, a once popular data transfer technology that has largely been displaced by faster SAS.
- A host bus adapter (HBA) is a circuit board and/or integrated circuit adapter that provides input/output (I/O) processing and physical connectivity between a host system, or server, and a storage and/or network device.
- Because an HBA typically relieves the host microprocessor of both data storage and retrieval tasks, it can improve the server's performance time.
- An HBA and its associated disk subsystems are sometimes referred to as a disk channel.
- A SAS HBA typically connects a server or workstation to a storage device such as a hard disk drive, solid-state drive, JBOD device or tape drive.
- SAS HBAs are able to connect to single- or dual-port storage devices that are compatible with the serial ATA or SAS interface.
- HBAs are typically defined by interconnect technology, speed, port count and system interface. An HBA is sometimes called an HBA card.
- The HBA card often plugs into the PCI Express (PCIe) slot of a server. Other HBA form factors include mezzanine cards for blade servers.