Serial ATA Cables / Interface Overview

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Serial Advanced Technology Attachment (known as "ATA"), or S-ATA, is a computer bus technology that was designed for the transfer of information/data to and from a computer hard disk drive. Serial ATA is the successor to Integrated Drive Electronics (IDE), sometimes also called Parallel ATA (or P-ATA). One of the advantages of Serial ATA is its simplicity one cable consisting of a minimum of four wires, allowing for connection in a point-to-point configuration between components/devices. Serial ATA transfer rates typically start at 150 Mega Bits per second (MBps), and can go as high as 600 MBps. Another advantage of Serial ATA cables is the thinner outline of the cable, allowing for efficient airflow within a computer or system enclosure, as well as allowing for smaller chassis design configurations. Power cables that are used for Serial ATA applications utilize a 15-pin wafer connector to deliver 3.3, 5, or 12 volts to ATA devices.

SATA revision 1.0 - 1.5 Gbit/s - 150 MB/s
Revision 1.0a was released on January 7, 2003. First-generation SATA interfaces, now known as SATA 1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s, and do not support Native Command Queuing (NCQ). Taking 8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s (150 MB/s). The theoretical burst throughput of SATA 1.5 Gbit/s is similar to that of PATA/133, but newer SATA devices offer enhancements such as NCQ, which improve performance in a multitasking environment.

During the initial period after SATA 1.5 Gbit/s finalization, adapter and drive manufacturers used a "bridge chip" to convert existing PATA designs for use with the SATA interface.Bridged drives have a SATA connector, may include either or both kinds of power connectors, and, in general, perform identically to their PATA equivalents. Most lack support for some SATA-specific features such as NCQ. Native SATA products quickly eclipsed bridged products with the introduction of the second generation of SATA drives.

As of April 2010 the fastest 10,000 RPM SATA mechanical hard disk drives could transfer data at maximum (not average) rates of up to 157 MB/s, which is beyond the capabilities of the older PATA/133 specification and also exceeds a SATA 1.5 Gbit/s link.

SATA revision 2.0 - 3 Gbit/s - 300 MB/s
Second generation SATA interfaces run with a native transfer rate of 3.0 Gbit/s, and taking 8b/10b encoding into account, the maximum uncoded transfer rate is 2.4 Gbit/s (300 MB/s). The theoretical burst throughput of SATA 3.0 Gbit/s is double that of SATA revision 1.0.

All SATA data cables meeting the SATA spec are rated for 3.0 Gbit/s and handle current mechanical drives without any loss of sustained and burst data transfer performance. However, high-performance flash drives can exceed the SATA 3 Gbit/s transfer rate; this is addressed with the SATA 6 Gbit/s interoperability standard.

SATA 3 Gbit/s is backward compatible with SATA 1.5 Gbit/s.

SATA revision 3.0 - 6 Gbit/s - 600 MB/s
Serial ATA International Organization presented the draft specification of SATA 6 Gbit/s physical layer in July 2008, and ratified its physical layer specification on August 18, 2008. The full 3.0 standard was released on May 27, 2009. It runs with a native transfer rate of 6.0 Gbit/s, and taking 8b/10b encoding into account, the maximum uncoded transfer rate is 4.8 Gbit/s (600 MB/s). The theoretical burst throughput of SATA 6.0 Gbit/s is double that of SATA revision 2.0. The 3.0 specification contains the following changes:

6 Gbit/s for scalable performance.
Continued compatibility with SAS, including SAS 6 Gbit/s. "A SAS domain may support attachment to and control of unmodified SATA devices connected directly into the SAS domain using the Serial ATA Tunneled Protocol (STP)" from the SATA_Revision_3_0_Gold specification.
Isochronous Native Command Queuing (NCQ) streaming command to enable isochronous quality of service data transfers for streaming digital content applications.
An NCQ Management feature that helps optimize performance by enabling host processing and management of outstanding NCQ commands.

Improved power management capabilities.
A small low insertion force (LIF) connector for more compact 1.8-inch storage devices.
A connector designed to accommodate 7 mm optical disk drives for thinner and lighter notebooks.
Alignment with the INCITS ATA8-ACS standard.

In general, the enhancements are aimed at improving quality of service for video streaming and high-priority interrupts. In addition, the standard continues to support distances up to one meter. The newer speeds may require higher power consumption for supporting chips, though improved process technologies and power management techniques may mitigate this. The later specification can use existing SATA cables and connectors, though it was reported in 2008 that some OEMs were expected to upgrade host connectors for the higher speeds.

The later standard is backward compatible with SATA 3 Gbit/s.

SATA revision 3.1
Released in July 2011, revision 3.1 introduced/changed these features:

mSATA, SATA for solid-state drives in mobile computing devices, a PCI Express Mini Card-like connector that is electrically SATA.
Zero-power optical disk drive, idle SATA optical drive draws no power.
Queued TRIM Command, improves solid-state drive performance.
Required Link Power Management, reduces overall system power demand of several SATA devices.
Hardware Control Features, enable host identification of device capabilities.
Universal Storage Module, a new standard for cableless plug-in (slot) powered storage for consumer electronics devices.

SATA revision 3.2 - 16 Gbit/s - 1969 MB/s
SATA Express specification defines an interface that combines both SATA and PCI Express buses, making it possible for legacy SATA and PCI Express storage devices to coexist; see the SATA Express section for a more detailed summary.

SATA M.2 standard is a small form factor implemenation of the SATA Express interface, with the addition of an internal USB 3.0 port; see the M.2 (NGFF) section for a more detailed summary.
microSSD introduces a ball grid array electrical interface for miniaturized, embedded SATA storage.
USM Slim reduces thickness of Universal Storage Module from 14.5 mm to 9 mm.
DevSleep enables lower power consumption for always on devices while in a mode such as Connected Standby.
Hybrid Information allows higher performance for solid-state hybrid drives.