Going the SAS Storage Way

Expanders

Source: Adaptec

Future SAS implementations will provide 600 and 1,200 MB/s bandwidth per port. As hard drive performance is not going to increase that much, it becomes obvious that using expanders on a limited amount of ports seems to be a good approach.

Devices called "Fan Out" and "Edge" both are expanders. However, only one Fan Out (primary) expander is allowed for a SAS domain (see 4X link to initiator in the middle of the image). There may be up to 128 physical links per edge expander - whether these are merged into wide links and/or linked to other expanders or drives. The result can be pretty complex, but equally powerful and flexible. Source: Adaptec.

Patrick Schmid
Editor-in-Chief (2005-2006)

Patrick Schmid was the editor-in-chief for Tom's Hardware from 2005 to 2006. He wrote numerous articles on a wide range of hardware topics, including storage, CPUs, and system builds.