Serial Attached SCSI (SAS) Connector Types
Internal SAS connections have evolved, and continue to evolve, but there is some confusion around the connection types. This guide aims to provide a brief overview of recent and current internal SAS cable connections. New connections are in development, but as at the time of writing, there isn't any SAS equipment that includes the new connections.
This guide refers only to the multi-lane SAS connectors on controllers, expanders, adapters and backplanes, and not the SAS connectors that attach to SAS hard-drives (which are known as SFF-8482 connectors).
Multilane SAS has up to 4-channels per port
SAS equipment with internal SAS ports can deliver connectivity for up to 4 channels, through a single port. Depending upon the SAS equipment, those SAS ports might additionally support extra connectivity known as sideband wiring, but sideband wiring is not essential, and the implementation can vary by manufacturer. As such, sideband wiring is not discussed in detail here.
Furthermore, SAS equipment can, and usually does, host multiple SAS ports. Some SAS controller cards have internal ports only, some have external ports only, and some might have a mix. This guide only deals with the internal cable connectors for internal ports.
Early internal SAS - SFF-8484
Early SAS equipment with internal SAS ports, make use of SFF-8484 connectors. These SFF-8484 connectors are sometimes called Wide-SAS or SAS-32 connectors, because they have 32 pins arranged in a single, straight line. The 32 pins accommodate up to 4 channels, plus any sideband wiring. The picture here depicts a SFF-8484 connector with one red cable per channel, and without any side-band wiring (Which would be in the middle gap, if it were shown).
Controllers such as the Dell Perc 5i use the SFF-8484 connector.
Current internal SAS - Mini SAS
As SAS has developed, and required faster and smaller interconnects, recent SAS connectors have been dubbed mini-SAS or mSAS connectors. The predominant connector is the 36 circuit SFF-8087, although a small number of devices do use a 26 circuit SFF-8086 connector.
The SFF-8087 connector has 36 pins, arranged in a stacked formation on a PCB. As a result, the connector is narrower, and more intricate. The SFF-8087 connector is the most common internal SAS connector on modrn SAS equipment. It usually has a latched connector, making accidental disconnects less likely.
Controllers such as the Dell H700 use the SFF-8087 connector.
The SFF-8086 connector has 26 pins arranged in a stacked formation on a PCB. As it has less pins, it results in a connector that is narrower than the 36 pin SFF-8087 connector. The SFF-8086 connector is the most rarely found connector on SAS hardware.
SAS connector inter-connectivity
It is possible to combine SAS equipment that use different SAS connectors (for example: SFF-8087 to SFF-8484 cables are available), but you should take note of the wiring and speed requirements, depending upon which 2 pieces of equipment you are connecting.
We hope that you have found this guide useful, and we'd appreciate your vote for this guide as helpful... Just click the voting button below.
If you feel that we've been unclear, made any errors, or omitted any critical details, please let us know.
If you need SAS or SATA equipment or accessories, please see our eBay store, or contact us with your requirements.