Port multipliers enable a SATA controller port to fan-out to multiple SATA devices. When a port multiplier is used, for example, in a storage enclosure or disk shelves, a single SATA port and cable can access multiple SATA disk drives. With the emergence of SAS and co-existence of SAS and SATA, you will start to hear more about SAS and SATA port multiplexers, multipliers, expanders and switches to facilitate connectivity between servers and storage arrays. These components are also found inside of storage systems between server and the storage controller and between storage controllers and disk drives.
Vendors to watch or learn more about if you are interested in SAS and SATA components include Broadcom, Intel, LSI Logic, PMC-Sierra and SiliconStor.
This was first published in April 2006