6Gb/s SAS Nomenclature and Logo Usage Guide
By Editor on May 28, 2011
SCSI and SAS standards developed by T10 have historically been given marketing names by the SCSI Trade Association (STA), for numerous reasons. In some cases, multiple T10 documents are required to describe a particular SAS generation. In other cases, the document names can contribute to a fair amount of market confusion, and at times, features made optional or required by T10 are inconsistent with market demands.
SAS Marketing Names: STA assigns a marketing name for each generation of the technology. 6Gb/s SAS is the marketing name based on the T10 Standards Committee SAS-2, SAS-2.1 and SPL technical specifications. All 6Gb/s SAS products produced and sold on the market largely comply with the SAS-2 standard, and are referenced as 6Gb/s SAS in this form. Because T10 uses more than just one document to describe the present generation of SAS technology, we strongly discourage companies from using the names of these technical specifications to describe their products.
6Gb/s SAS Features: 6Gb/s SAS products have, as a minimum, the following features: 6Gb/s transfers, external Mini-SAS or Mini-SAS HD (recently added) connectors, Spread Spectrum Clocking (SSC), Standardized Expander Zoning, Self-discovering Expanders, and (optionally) Multiplexing. In all cases, these capabilities must be consistent with, and meet or exceed, the implementation details defined by T10.
SAS-2.1 is a minor revision of the SAS-2.0 specification, but focuses only on the physical elements of the protocol. A new T10 specification, the SAS Protocol Layer (SPL), includes the remaining elements of the logical protocol. This structure, dividing the physical layer from the protocol layer, will continue for future SAS generations as well. Nearly all 2nd generation SAS products were designed and implemented in accordance with SAS-2.1 and SPL, and as such, do not represent a new generation of SAS. Products implemented to the SAS-2.1 and SPL draft specifications (now out for public vote, and expected to be forwarded to INCITS in August 2010) will continue to be referenced as 6Gb/s SAS.
Examples of historic misuse of SAS terminology: SAS2, SAS 2.0, 6G, 6GSAS, 6G SAS, 6GbsSAS, 6Gbps SAS, 6Gb/s, SAS 300, SAS 600, SAS 1200.