
The signaling equals to what is used in SATA. Source: Adaptec.
Here comes the neat thing: Serial Attached SCSI supports both SCSI and SATA, which enables SAS controllers to run either SAS or SATA devices (or both). However, SAS devices cannot be operated on SATA controllers because the Serial SCSI Protocol (SSP) is used. Like SATA, SAS follows the principle of point-to-point links to the drives (currently 300 MB/s), while there is the option to use SAS expanders for attaching more drives than SAS ports available. SAS hard drives are dual-ported, each featuring his unique SAS ID, which means that it is possible to use two physical data connections to provide redundant data paths to two different hops/hosts. Thanks to STP (SATA Tunneling Protocol), SAS controllers will still be able to talk to SATA drives that are attached to an expander.

Source: Adaptec

Source: Adaptec
- SAS Raises Storage Capabilities To Higher Power
- SCSI's Details And History
- From SATA
- SAS
- Expanders
- SAS Backplanes & Cables
- SAS As Part Of SAN Storage Solutions
- 2.5" SAS Hard Drives
- Fujitsu MAY2073RC
- 3.5" SAS Hard Drives
- Hitachi UltraStar 15K147 SAS (HUS151414VLS300)
- Maxtor Atlas 15KII
- Seagate Cheetah 15K.4B 147 GB (ST3146854SS)
- Host Adapters
- Adaptec SAS 48300
- RAID Adapters
- LSI Logic SAS3442X
- SAS Appliances And Enclosures
- Storage System
- Adaptec SANbloc S50 JBOD, Continued
- Test Setup
- Hard Drive Test Results
- 3.5" SAS Data Transfer Diagrams
- Data Transfer Performance
- Access Time
- I/O Performance
- SAS RAID Test Results (4 And 10 Drive Arrays)
- Conclusion
Create a new thread in the Reviews comments forum about this subject
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0 Hidewdanforth , September 10, 2008 2:52 AMThank you for the SAS lesson.
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0 Hidevinay_20 , December 12, 2011 11:44 AMIt was a nice jest for SAS.