SATA vs SAS Hard Drives

SATA hard drives VS SAS hard drives what is the difference? While both of these systems are designed to bring data from the motherboard and into storage and carry out other similar tasks there are some main differences and they are:


  • SAS is typically more expensive. These drives are used heavily in processing intensive workstations and servers.

  • SATA is typically less expensive and is best suited for a desktop for file storage.


So what makes SAS, SAS and what makes SATA, SATA? Are the drives different? Are the cables the reason?


SATA explained


SATA stands for “serial advanced technology attachment.” Advanced technology attachment (ATA) was the previous form of the technology that was used in the parallel communication days. SATA replaces it.

SATA is implemented in 2 areas:

  • A SATA cable

  • SATA connectors, to which the cable hooks up


You’ll find SATA connectors on compatible motherboards and hard drives. Note that SATA isn’t a storage drive in and of itself. Rather, storage drives may be built with SATA connectors.

The SATA interface is built with:

  • 2 conductors for sending data

  • 2 conductors for retrieving data

  • Ground cables in between the conductors to prevent interference


It also has a power cable that powers the internal storage drive .

SAS explained

SAS in SAS hard drives, stands for “serial attached SCSI.” SCSI stands for “small computer systems interface.” SCSI was the former parallel technology that SAS has replaced.

SAS has a similar build to that of SATA:

  • conductors for sending data

  • 2 conductors for receiving data

  • Ground cables in between the conductors to reduce interference

Difference between SATA and SAS

But here’s where SAS differs. In a SATA cable, all 4 wires are placed within the same cable. In a SAS cable, the 4 wires are separated into 2 different cables. This isn’t parallel technology; each cable still houses both an incoming and outgoing wire.

Why divide the wires between 2 cables? So you can connect more devices to one another. With a SATA cable, you can only link the motherboard and the storage drive. You could hook up an expansion device, but that takes up valuable room inside your computer.

With a SAS cable, you can hook up the motherboard to both a storage drive and another piece of hardware that has SAS connectors.

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