Short Overview on SAS Device
Paul on December 17th, 2010
SAS device is an interface for serial data transfer. Actually SAS is the replacement to SCSI (Small Computer System Interface) parallel, but still uses SCSI commands for interacting with SAS devices. SAS increases speed and allows the switching on and off quickly.
The organization behind the development of the SAS specification is the SCSI Trade Association. It is a nonprofit organization based in California that was formed in 1996 to promote the use and knowledge of parallel SCSI.
The first version appeared in late 2003. SAS 300, which got a bandwidth of 3Gb / s, which considerably increased the speed of its predecessor (Ultra SCSI 320MB / s). The next evolution, SAS 600, reach speeds of up to 6Gb / s, while it is expected to reach a speed of about 12Gb / s around 2010.
One of the main characteristic is that it increases the transmission rate by increasing the number of connected devices, so it can handle transfer rate constant for each connected device. In addition to end the present limit of 16 SCSI devices, it is expected that SAS technology will replace its SCSI prototype.
In addition, the connector is the same as SATA interface and allows you to use these hard drives for applications with less need for speed, cost savings. Therefore, the SATA controllers can be used by SAS but not the reverse, a parent does not recognize SATA disks SAS.
It is designed to allow higher transfer rates and be compatible with SATA, and allows up to 16384 addressable devices in a SAS domain. This is possible thanks to the SAS domain, which are a set of ports that communicate with each other.
Overall, SAS drives are not cheap they are rather expensive, but in terms of features and performance most of the dedicated server hosting providers included SAS drives in their hosting plans.
