SATA Explained / Connector Pin-Out

What is SATA?
SATA is an evolutionary replacement for the Parallel ATA physical storage interface. SATA is scalable and allows for enhancements to the computing platform. These include easier integration, faster performance, and more efficient design.

How will the industry benefit from adopting SATA?
Adoption of the Serial ATA specification provides low-cost storage for the industry, improved speed and bandwidth, and serves as an evolutionary replacement for the Parallel ATA interface. Implementation of Serial ATA allows for easy integration due to improved cabling, greater flexibility in regard to system configuration and hot plugability. With these enhancements, system builders can create new solutions with fewer limitations and will experience greater interoperability with other interfaces.

What are the end user benefits of SATA?
End users will benefit by being able to easily upgrade their storage devices. Configuration of SATA devices will be much simpler, with many of today's requirements on jumper and settings no longer needed. Advancements in the SATA specifications also allow improvements and scalability in performance for the storage interface.

What are the IT management benefits of using SATA?
SATA provides:
• Enhanced performance (faster transfer rate and NCQ)
• Enhanced reliability (expanded CRC and latching connectors)
• System integration flexibility

How does the end-user benefit from using SATA technology in servers and NAS?
User benefits for servers and NAS include:
• Hotplug/backplane
• Enclosure management
• Interoperability with SAS
• Backward compatibility with various speeds
• Higher performance
• Ease of integration – no more jumpers
• Improved air flow

Does SATA provide better performance than Parallel ATA?
Serial ATA supports data rates up to 6Gb/s, versus the embraced industry standard of 100 MB/s for Parallel ATA. The new interface also provides for command queuing to further boost system performance.

Desktops, Mobile PCs, and Consumer Electronics

 What connector options are available for SATA devices?
The SATA Revision 2.6 Specification defines the following connectors: an internal slimline cable and connector that enables SATA optical drives to achieve a smaller form factor; an internal Micro-SATA connector for 1.8-inch hard disk drives which facilities high-capacity SATA-based storage in ultra-mobile PC applications; and a mini-SATA internal/external multi-lane cable and connector that provides high-bandwidth connectivity for use in internal backplane designs and external eSATA or xSATA based protocols for external storage enclosures.

In additon to those listed above, SATA-IO offers two new connectors in the SATA Revision 3.0 Specification: the Low Insertion Force (LIF) connector for compact embedded storage applications, and the 7mm connector for optical disk drives, enabling thinner and lighter mobile notebook PCs.

What is eSATA?
External SATA (eSATA) is an external version of SATA that uses slightly different connectors that withstand wear and tear and static electricity. eSATA offers faster speed and better performance than existing external storage formats such as USB 2.0 and FireWire (IEEE 1394).

What are the benefits of using eSATA?

  • Up to six times faster than existing external storage solutions
  • Robust and user-friendly external connection
  • High-performance and cost-effective expansion storage
  • Up to two meter shielded cables and connectors
  • Port multiplication to attach multiple disk drives on a single eSATA cable
  • External Direct Attached Storage applications for notebooks, desktop, consumer electronics and entry servers, as well as support for multiple streams of content (such as parallel write and read on a digital video recorder, or DVR)

 

Servers and Networked Storage

 

What are the compelling reasons why SATA is a viable option for server and NAS networked storage?
Scalability—SATA is a point-to-point connection and allows multiple ports to be aggregated into a single controller that is typically located either on the motherboard or as an add-in RAID card. Through backplanes and external enclosures, SATA will be deployed in high-capacity server and networked-storage environments.

Cost—SATA was created, with desktop cost in mind, as a replacement for Parallel ATA. Initial hard disk drives (HDDs) are expected to be priced competitively for the desktop. With the scalable features of SATA combined with desktop price-points, greater storage capacity may be realized at a lower total solution cost than with traditional server and networked storage.

Cabling—SATA specifies a thin, point-to-point connection, which allows for easy cable routing within a system. This avoids master/slave, "daisy-chaining", and termination issues. Also, better airflow can be realized compared to systems with wider ribbon cables.

Performance—SATA technology delivers up to 6Gb/s of performance to each drive within a disk drive array.


Connectors

Connectors and cables present the most visible differences between SATA and parallel ATA drives. Unlike PATA, the same connectors are used on 3.5-inch (89 mm) SATA hard disks for desktop and server computers and 2.5-inch (64 mm) disks for portable or small computers; this allows 2.5-inch (64 mm) drives to be used in desktop computers with only a mounting bracket and no wiring adapter. Smaller disks may use the mini-SATA spec, suitable for small-form-factor Serial ATA drives and mini SSDs. 

There is a special connector (eSATA) specified for external devices, and an optionally implemented provision for clips to hold internal connectors firmly in place. SATA drives may be plugged into SAS controllers and communicate on the same physical cable as native SAS disks, but SATA controllers cannot handle SAS disks.

There are female SATA ports (on motherboards for example) for use with SATA data cable with locks or clips, thus reducing the chance of accidentally unplugging while the machine is turned on—As do SATA power/data connectors on optical and high-density devices. Moreover, some SATA cables have orthogonally positioned heads in the shape of an 'L' which in effect ease the connection of devices to circuit boards.

Pin-Out Configuration

 

Standard Data connector

Pin # Function
1 Ground
2 A+ (transmit)
3 A− (transmit)
4 Ground
5 B− (receive)
6 B+ (receive)
7 Ground
 — Coding notch

 

Standard Power Connector

Pin # Mating Function
 — Coding notch

1 3rd 3.3 V
2 3rd
3 2nd

4 1st Ground
5 2nd
6 2nd

7 2nd 5 V
8 3rd
9 3rd

10 2nd Ground

11 3rd Staggered spinup/activity
(in supporting drives)

12 1st Ground

13 2nd 12 V
14 3rd
15 3rd

 

Slimline Connector

Pin # Mating Function
 — Coding notch

1 3rd Device presence

2 2nd 5 V

3 2nd

4 2nd Manufacturing diagnostic

5 1st Ground

6 1st

 

Micro Connector

Pin # Mating
(Backplane)
Function

1 3rd 3.3 V

2 2nd

3 1st Ground

4 1st

5 2nd 5 V

6 3rd

7 3rd Reserved
 — Coding notch

8 3rd Vendor specific

9 2nd