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SAS Advanced Connectivity

Serial Attached SCSI (SAS) burst upon the storage scene in 2004 as a serial replacement for the once ubiquitous parallel SCSI interconnect. While much attention is often given to the capabilities of the protocol and to the silicon and software required to implement these systems, it is often the physical interconnections that influence the adoption of I/O in a variety of market segments. Parallel SCSI, for example, supported everything necessary for clustered server deployments; however, the large unwieldy nature of the parallel cables and the restricted cabling distances greatly limited SCSI's applicability in these markets.
SAS removed many of these restrictions by opening up the bandwidth, improving cabling distances, and providing a compact connection scheme suitable for today's shrinking data center. While first generation solutions made tremendous strides forward, the connection schemes have continued to improve, opening up new markets for SAS in the process.
Below please find links to several useful documents that will help you learn about SAS Advanced Connectivity. Below the links, you will find a Frequently Asked Questions & accompanying answers.







SAS Advanced Connectivity Roadmap
Frequently Asked Questions

Q1. What is the Advanced Connectivity Roadmap?

A1. The Advanced Connectivity roadmap is STA's connectivity roadmap to guide the industry through future SAS storage solutions. It specifies the Mini-SAS High Density (HD) (SFF- 8643/8644) connector as the converged connectivity scheme for SAS-based deployments and in addition, defines the SAS Connectivity Management scheme for simplifying cable and connectivity management.
Q2. Name the factors that stimulated provision of the Advanced SAS Connectivity Roadmap.
A2. Factors which drove provision of the Advanced SAS Connectivity Roadmap include simplification of cable and connector options and the provision of managed connectivity standards. Additional factors include providing high-density connectivity and the extension of active copper cable to 20m and optical cable to 100m.
Q3. What is a Mini-SAS High Density (HD) connector and how does it improve connectivity?
A3. The Mini-SAS HD connector doubles the port density over the Mini-SAS connector. Both internal and external solutions are available and it is electrically improved with less cross-talk and a much better signal-to-noise ratio. It supports active copper and optical cabling as well as SAS Connectivity Management.
Q4. What advantages result by extending copper cables to 20m or optical cables to 100m provide to SAS storage systems?
A4. Longer cables enable more box-to-box, server-to-storage and rack-to-rack connections, thereby providing greater scalability (permitting accommodation of more spindles). Longer cables also allow greater configuration deployment flexibility.
Q5. In which external storage applications is 6Gb/s SAS now advancing dramatically?
A5. Currently, 6Gb/s SAS has made significant advances in drive-attach and there is a growing opportunity for host-attached applications as well.
Q6. Will Advanced SAS Connectivity extend beyond 6Gb/s SAS?
A6. Yes, it will be extended to 12Gb/s SAS when this next SAS generation enters the market.
Q7. What is SAS Connectivity Management?
A7. SAS Connectivity Management is a consistent way of managing the cabling plan in any SAS system using the Mini-SAS HD connector. It is capable of detecting the presence or absence of a cable, number of SAS ports within the connector, what type of connection is being supported, (active, passive, optical), and other attributes important to storage system usability and serviceability.
Q8. What can Advanced SAS Connectivity contribute to cloud computing, large data centers and massive data enterprises?
A8. Advanced SAS Connectivity provides greater distance, flexibility, scalability, serviceability and usability to large-size storage installations and uses.
Q9. What are the primary advantages of SAS Connectivity Management?
A9. SAS Connectivity Management defines connectivity support including connection discovery and cable management; improved serviceability and usability without the need for mechanical keys; it also provides rapid fault isolation and minimal configuration errors; and last, it lowers Total Cost of Ownership (TCO).
Q10. In which SAS generation will SAS Connectivity Management appear?
A10. SAS Connectivity Management may be implemented rather quickly on the existing 6Gb/s SAS generation supported by the QSFP connector. While STA recognizes that some homogeneous deployments may use this connector, it is not the preferred connector for heterogeneous deployments. Mini-SAS HD systems are expected to take advantage of SAS Connectivity Management. These advantages will appear in the current 6Gb/s SAS generation, possibly in the first half of 2010. They will appear subsequently in the 12Gb/s SAS generation.

Press Releases

SAN FRANCISCO, October 12, 2009 -SCSI Trade Association (STA) is introducing the new Serial Attached SCSI (SAS) Advanced Connectivity Roadmap which previews the connectivity advances to support future SAS growth in the enterprise. The new SAS connectivity benefits will apply to mid-range and large data centers and will improve all aspects of connectivity and ease of operation.

As an important part of the announcement, STA is promoting a converged Mini-SAS High-Density (HD) standard connector to create a vibrant and consistent infrastructure to expand SAS usability and scalability. The STA objectives include a consistent connectivity management scheme in addition to the active copper and optical cable extensions supported by the new Mini-SAS HD connector.


SAS Advanced Connectivity Webinar


On September 16, STA President Marty Czekalski presented an update on SCSI standards and technology at Storage Developer Conference in Santa Clara, CA.

Topics include:

  • SCSI Express
  • New SCSI features for flash and performance, including extended copy, atomic operations, hinting, SCSI-SF, and power limit control
  • Express Bay
  • Beyond 12Gb/s SAS
  • Advanced Connectivity
  • 24Gb/s SAS MRD
  • Shingled Magnetic Recording

Download the presentation here: SDC-SCSI Standards and Technology Update 2014 r5.pdf

Presenters: Harry Mason, President, SCSI Trade Association
                       Marty Czekalski, Vice President, SCSI Trade Association
Where:   Storage Networking World Fall 2011, Orlando, FL
When:   October 12, 2011

In this presentation Mason and Czekalski present:

  • Update on the SCSI Trade Association
  • Range of SAS & SATA storage solutions
  • SAS technology and market overview
  • Key markets and sample deployments
  • Extending SAS innovation
    • 12Gb/s
    • MultiLink SAS™
    • Advanced Connectivity

Download presentation...

SAS Standards and Technology Update

Presenters: Harry Mason, President SCSI Trade Association, and Director of Industry Marketing at LSI, Corp.
                Marty Czekalski, Vice President SCSI Trade Association, and Interface & Emerging Architecture
                Program Manager at Seagate
Where: Storage Developers Conference, Santa Clara, CA
When: September 19, 2011

In this presentation Mason and Czekalski provide:

  • SAS Overview
  • SAS Performance Roadmap and 12Gb/s SAS staging
  • MultiLink SAS™ and Advanced Connectivity
  • SCSI over PCIe (SOP)
  • Backplane Receptacle Compatibility

Download presentation...

Extending SAS Innovation in 2011

Extending SAS innovation:

  • 12Gb/s SAS
  • MultiLink SAS™
  • Advanced Connectivity


What You Should Know about SAS

By: Harry Mason, President SCSI Trade Association, Director of Marketing, LSI
Where: FOSE Conference & Exhibition, Washington, DC
When: July 11 - 14, 2011

Mason presents an overview of the SCSI Trade Association, SAS technology and the market for SAS products and technology, including key markets, sample deployments and what SAS innovations will present in the future.