SAS is the preferred interface for the direct-attach server space, SCSI's former mainstay. SAS is for mission critical applications that require higher levels of availability and native expansion. SAS is optimised for the random performance requirements of the data centre. The 9690SA's advanced RAID features, SAS connectivity, and powerful 3ware performance architecture make it the ideal SCSI controller replacement for data centre and Web server usage. It's everything you ask for from a controller: quick, consistent and reliable. As an added bonus you get more cache compared to competing models from LSI Logic and Adaptec.