question Adaptor cables

[Bozo]

Has anyone used a SAS to SATA cable? Do you need a separate SATA controller, or can you use the motherboard SATA connectors?

 

[LunarMist]

Do you mean an SFF type breakout cable? A single channel SATA connector is the same as that for SATA. Some embedded controllers support both SATA and SAS, but some don't. Normally if it supports SAS that will be indicated in the literature.

 

[Bozo]

The cable is one that allows the use of a SAS hard drive on a SATA controller.

 

[MaxBurn]

Not aware that there is such a thing.

 

[Stereodude]

I don't think you can use a SAS drive on a SATA controller.

 

[sdbardwick]

I don't think you can use a SAS drive on a SATA controller.

I don't think so either. The wire link is the same, but the SATA controller speaks ATA, while the SAS drive speaks SCSI.

 

[sdbardwick]

Edit time expired: But SAS controllers can talk to SATA drives, as far as I can tell.

 

[ddrueding]

AFAIK, SATA is a subset of the SAS command set.

 

[sdbardwick]

From Adaptec via ixbtlabs.com:

Physical layers
The SAS connector is a universal interconnection that is form-factor compatible with SATA. It allows SAS or SATA drives to plug directly into a SAS environment for mission-critical applications with high-availability and high-performance requirements or lower-cost-per-gigabyte applications such as near-box storage.

SATA connector signals are a subset of SAS signals that enable the compatibility of SATA devices and SAS controllers. SAS drives will not operate on a SATA controller and are keyed to prevent any chance of plugging them in incorrectly.

In addition, the similar SAS and SATA physical interfaces enable a new universal SAS backplane that provides connectivity to both SAS drives and SATA drives. This eliminates the need for separate SCSI and ATA drive backplanes. This consolidation of designs greatly benefits both backplane manufacturers and end users by reducing inventory and design costs.

Protocol layer
SAS consists of three types of protocols, each of which is used to transfer different types of data over the serial interface, depending on which device is being accessed. Serial SCSI Protocol (SSP) transfers SCSI commands, and SCSI Management Protocol (SMP) sends management information to expanders. Meanwhile, SATA Tunneled Protocol (STP) creates a connection that allows transmission of the SATA commands. By including all three of these protocols, SAS provides seamless compatibility with today's existing SCSI applications, management software and SATA devices.

This multi-protocol architecture support, coupled with the compatibility of SAS and SATA's physical connection, allows SAS to operate as the universal interconnection for both SATA and SAS devices.

 

[LunarMist]

I'm not quite sure which cable is mentioned, but does the controller claim to support SAS or not?