Serial ATA - Wikipedia, The Free Encyclopedia

SATASerial ATA

First-generation (1.5 Gbit/s) SATA ports ona motherboard

Year created: 2003Supersedes: Parallel ATA (PATA)

Capacity 1.5, 3.0, 6.0 Gbit/sStyle: SerialHotplugging? Yes[1]

External? Yes (eSATA)

Serial ATAFrom Wikipedia, the free encyclopedia

The serial ATA, or SATA computer bus, is a storage-interface forconnecting host bus adapters to mass storage devices such as harddisk drives and optical drives. The SATA host adapter is integratedinto almost all modern consumer laptop computers and desktopmotherboards.

Serial ATA was designed to replace the older ATA (AT Attachment)standard (also known as EIDE). It is able to use the same low levelcommands, but serial ATA host-adapters and devices communicate viaa high-speed serial cable over two pairs of conductors. In contrast, theparallel ATA (the redesignation for the legacy ATA specifications)used 16 data conductors each operating at a much lower speed.

SATA offers several compelling advantages over the older parallelATA (PATA) interface: reduced cable-bulk and cost (reduced fromeighty wires to seven), faster and more efficient data transfer, and hotswapping.

As of 2009, SATA has mostly replaced parallel ATA in all shippingconsumer PCs. PATA remains in industrial and embedded applicationsdependent on CompactFlash storage although the new CFast storagestandard will be based on SATA.[2][3]

Contents1 SATA specification bodies2 Features

2.1 Hotplug2.2 Advanced Host Controller Interface

3 Throughput3.1 SATA 1.5 Gbit/s (First generation)3.2 SATA 3 Gbit/s (Second generation)

3.2.1 SATA II committee renamed SATA-IO3.2.2 SATA II product marketing

3.3 SATA 6 Gbit/s (Third generation)

4 Cables, connectors, and ports4.1 Data4.2 Power supply

4.2.1 Standard connector

11/7/2009 Serial ATA - Wikipedia, the free encyclo…

http://en.wikipedia.org/wiki/Serial_ATA 1/14

4.2.2 Slimline connector4.2.3 Micro connector

5 Topology6 Encoding7 External SATA8 Pre-standard implementations9 Backward and forward compatibility

9.1 SATA and PATA9.2 SATA 1.5 Gbit/s and SATA 3 Gbit/s

10 Comparisons with other interfaces10.1 SATA and SCSI10.2 SATA in comparison to other buses

11 See also12 Notes and references13 External links

SATA specification bodiesThere are at least four bodies with possible responsibility for providing SATA specifications: the trade organisation,SATA-IO; the INCITS T10 subcommittee (SCSI); a subgroup of T10 responsible for SAS; and the INCITS T13subcommittee (ATA). This has caused confusion as the ATA/ATAPI-7 specification from T13 incorporated anearly, incomplete SATA rev. 1 specification from SATA-IO.[4] The remainder of this article will try to use theterminology and specifications of SATA-IO.

Features

Hotplug

All SATA devices support hotplugging. However, proper hotplug support requires the device be running in itsnative command mode not via IDE emulation, which requires AHCI (Advanced Host Controller Interface). Someof the earliest SATA host adapters were not capable of this and furthermore some older operating systems, such asWindows XP, do not directly support AHCI.

Advanced Host Controller Interface

As their standard interface, SATA controllers use the AHCI (Advanced Host Controller Interface), allowingadvanced features of SATA such as hotplug and native command queuing (NCQ). If AHCI is not enabled by themotherboard and chipset, SATA controllers typically operate in "IDE emulation" mode which does not allowfeatures of devices to be accessed if the ATA/IDE standard does not support them.

Windows device drivers that are labeled as SATA are usually running in IDE emulation mode unless they explicitlystate that they are AHCI. While the drivers included with Windows XP do not support AHCI, AHCI has beenimplemented by proprietary device drivers.[5] Windows Vista,[6] Windows 7, FreeBSD, Linux with kernel version2.6.19 onward,[7] as well as Solaris and OpenSolaris have native support for AHCI.



ThroughputThe current SATA specifications detail data transfer rates as high as 6.0 Gbit/s per device. SATA uses only 4 signallines; cables are more compact and cheaper than PATA. SATA supports hot-swapping and NCQ.

SATA 1.5 Gbit/s (First generation)

First-generation SATA interfaces, now known as SATA 1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s. Taking8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s. The theoreticalburst throughput of SATA 1.5 Gbit/s is similar to that of PATA/133, but newer SATA devices offer enhancementssuch as NCQ which improve performance in a multitasking environment.

As of April 2009 mechanical hard disk drives can transfer data at up to 131 MB/s,[8] which is within the capabilitiesof the older PATA/133 specification. However, high-performance flash drives can transfer data at up to201 MB/s.[9] SATA 1.5 Gbit/s does not provide sufficient throughput for these drives.

During the initial period after SATA 1.5 Gbit/s finalization, adapter and drive manufacturers used a "bridge chip" toconvert existing PATA designs for use with the SATA interface. Bridged drives have a SATA connector, mayinclude either or both kinds of power connectors, and generally perform identically to their PATA equivalents. Mostlack support for some SATA-specific features such as NCQ. Bridged products gradually gave way to nativeSATA products.

SATA 3 Gbit/s (Second generation)

Soon after the introduction of SATA 1.5 Gbit/s, a number of shortcomings emerged. At the application level SATAcould handle only one pending transaction at a time—like PATA. The SCSI interface has long been able to acceptmultiple outstanding requests and service them in the order which minimizes response time. This feature, nativecommand queuing (NCQ), was adopted as an optional supported feature for SATA 1.5 Gbit/s and SATA 3 Gbit/sdevices.

First-generation SATA devices operated at best a little faster than parallel ATA/133 devices. Subsequently, a3 Gbit/s signaling rate was added to the physical layer (PHY layer), effectively doubling maximum data throughputfrom 150 MB/s to 300 MB/s.

For mechanical hard drives, SATA 3 Gbit/s transfer rate is expected to satisfy drive throughput requirements forsome time, as the fastest mechanical drives barely saturate a SATA 1.5 Gbit/s link. A SATA data cable rated for1.5 Gbit/s will handle current mechanical drives without any loss of sustained and burst data transfer performance.However, high-performance flash drives are approaching SATA 3 Gbit/s transfer rate.

Given the importance of backward compatibility between SATA 1.5 Gbit/s controllers and SATA 3 Gbit/s devices,SATA 3 Gbit/s autonegotiation sequence is designed to fall back to SATA 1.5 Gbit/s speed when incommunication with such devices. In practice, some older SATA controllers do not properly implement SATAspeed negotiation. Affected systems require the user to set the SATA 3 Gbit/s peripherals to 1.5 Gbit/s mode,generally through the use of a jumper, however some drives lack this jumper. Chipsets known to have this faultinclude the VIA VT8237 and VT8237R southbridges, and the VIA VT6420, VT6421A and VT6421L standaloneSATA controllers.[10] SiS's 760 and 964 chipsets also initially exhibited this problem, though it can be rectified withan updated SATA controller ROM.



SATA II committee renamed SATA-IO

Popular usage refers to the SATA 3 Gbit/s specification as Serial ATA II (SATA II or SATA2), contrary to thewishes of the Serial ATA International Organization (SATA-IO) which defines the standard. SATA II wasoriginally the name of a committee defining updated SATA standards, of which the 3 Gbit/s standard was just one.However since it was among the most prominent features defined by the former SATA II committee, and, morecritically, the term "II" is commonly used for successors, the name SATA II became synonymous with the 3 Gbit/sstandard, so the group has since changed names to the Serial ATA International Organization, or SATA-IO, toavoid further confusion.

SATA II product marketing

As of 2009, "SATA II" and "SATA 2" are the most common marketing terms for any "second-generation" SATAdrives, controllers or related accessories. Unfortunately, these terms have no specific meaning, since they are notthe proper official nomenclature. Also, the second-generation SATA standards only define a set of optional features(3 Gb/s, NCQ — Native Command Queuing, staggered spin-up and hot-plugging) improving on the first generationtechnology, but don't require including those features. Almost any SATA product with any set of features couldlegitimately be described as "compatible" with these standards. Only careful research can determine which featuresmay be included in any particular "SATA II" product. [11] [12]

SATA 6 Gbit/s (Third generation)

Serial ATA International Organization presented the draft specification of SATA 6 Gbit/s physical layer in July2008,[13] and ratified its physical layer specification on August 18, 2008.[14] The full 3.0 standard was released onMay 27, 2009.[15] While even the fastest conventional hard disk drives can barely saturate the original SATA 1.5Gbit/s bandwidth, Solid State Disk drives are close to saturating the SATA 3 Gbit/s limit at 250 MB/s net readspeed. Ten channels of fast flash can reach well over 500 MB/s with new ONFI drives, so a move from SATA 3Gbit/s to SATA 6 Gbit/s would benefit the flash read speeds. As for the standard hard disks, the reads from theirbuilt-in DRAM cache will end up faster across the new interface.[16]

The new specification contains the following changes:

A new Native Command Queuing (NCQ) streaming command to enable Isochronous data transfers forbandwidth-hungry audio and video applications.An NCQ Management feature that helps optimize performance by enabling host processing and managementof 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.

The enhancements are generally aimed at improving quality of service for video streaming and high priorityinterrupts. In addition, the standard continues to support distances up to a meter. The new speeds may requirehigher power consumption for supporting chips, factors that new process technologies and power managementtechniques are expected to mitigate. The new specification can use existing SATA cables and connectors, althoughsome OEMs are expected to upgrade host connectors for the higher speeds.[17] Also, the new standard is



Pin # Function

1 Ground

2 A+ (Transmit)

3 A− (Transmit)

4 Ground

5 B− (Receive)

6 B+ (Receive)

7 ground

8 coding notch

some OEMs are expected to upgrade host connectors for the higher speeds. Also, the new standard isbackwards compatible with SATA 3 Gbit/s.[18]

In order to avoid parallels to the common SATA II misnomer, the SATA-IO has compiled a set of marketingguidelines for the new specification. The specification should be called Serial ATA International Organization:Serial ATA Revision 3.0, and the technology itself is to be referred to as SATA 6 Gbit/s. A product using thisstandard should be called the SATA 6 Gbit/s [product name]. The terms SATA III or SATA 3.0, which areconsidered to cause confusion among consumers, must not be used.[19]

Cables, connectors, and portsConnectors and cables present the most visible differences between SATA and parallel ATA drives. Unlike PATA,the same connectors are used on 3.5 in SATA hard disks for desktop and server computers and 2.5 in disks forportable or small computers; this allows 2.5 in drives to be used in desktop computers with only a mounting bracketand no wiring adapter. Smaller disks may use the mini-SATA spec, suitable for small-form-factor Serial ATAdrives and mini SSDs. [20]

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

There are SATA ports (on motherboards of a PC) that can use SATA data cable with locks or clips, thus, reducingthe chance of accidentally unplugging while the PC is turned on. So does the same with SATA power connectorand SATA data connector connected to a SATA HDD or SATA optical drive. Also, there are right-angled andleft-angled connectors only on one end of SATA data cable, which can only be used when connecting to a SATAHDD or SATA optical drive.

Data

The SATA standard defines a data cable with seven conductors (3grounds and 4 active data lines in two pairs) and 8 mm wide waferconnectors on each end. SATA cables can have lengths up to 1 metre(3.3 ft), and connect one motherboard socket to one hard drive. PATAribbon cables, in comparison, connect one motherboard socket to up totwo hard drives, carry either 40 or 80 wires, and are limited to45 centimetres (18 in) in length by the PATA specification (however,cables up to 90 centimetres (35 in) are readily available). Thus, SATAconnectors and cables are easier to fit in closed spaces and reduceobstructions to air cooling. They are more susceptible to accidentalunplugging and breakage than PATA, but cables can be purchased thathave a locking feature, whereby a small (usually metal) spring holds theplug in the socket.

One of the problems associated with the transmission of data at highspeed over electrical connections is loosely described as noise. Despiteattempts to avoid it, some electrical coupling will exist both between datacircuits and between them and other circuits. As a result, the data circuitscan both affect other circuits, whether they are within the same piece ofequipment or not, and can be affected by them. Designers use a number



A 7-pin Serial ATA right-angle data cable.

Pin # Mating Function

— coding notch

1 3rd

3.3 V2 3rd

3 2nd

4 1st

Ground5 2nd

6 2nd

7 2nd

5 V8 3rd

9 3rd

10 2nd Ground

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

12 1st Ground

13 2nd

12 V14 3rd

15 3rd

A 15-pin Serial ATA power receptacle. This connector does notprovide the extended pins 4 and 12 needed for hot-plugging.

of techniques to reduce the undesirable effects of such unintentionalcoupling. One such technique used in SATA links is differential signaling.This is an enhancement over PATA, which uses single-ended signaling.Twisted pair cabling also gives superior performance in this regard.

Power supply

Standard connector

The SATA standard specifies a different powerconnector than the decades-old four-pin Molexconnector found on pre-SATA devices. Like the datacable, it is wafer-based, but its wider 15-pin shapeprevents accidental mis-identification and forcedinsertion of the wrong connector type. Native SATAdevices favor the SATA power-connector, althoughsome early SATA drives retained older 4-pin Molex inaddition to the SATA power connector.

SATA features more pins than the traditionalconnector for several reasons:

A third voltage is supplied, 3.3 V, in addition tothe traditional 5 V and 12 V.Each voltage transmits through three pinsganged together, because the small contacts bythemselves cannot supply sufficient current forsome devices. (Each pin should be able toprovide 1.5 A.)Five pins ganged together provide ground.For each of the three voltages, one of the threepins serves for hotplugging. The ground pins andpower pins 3, 7, and 13 are longer on the plug(located on the SATA device) so they willconnect first. A special hot-plug receptacle (onthe cable or a backplane) can connect groundpins 4 and 12 first.Pin 11 can function for staggered spinup, activityindication, or nothing. Staggered spinup is usedto prevent many drives from spinning upsimultaneously, as this may draw too muchpower. Activity is an indication of whether thedrive is busy, and is intended to give feedbackto the user through a LED.

Adapters exist which can convert a 4-pin Molex connector to a SATA power connector. However, because the 4-pin Molex connectors do not provide 3.3 V power, these adapters provide only 5 V and 12 V power and leave the



Pin # Function

1 Device Present

25 V

3

4 Manufacturing Diagnostic

5Ground

6 A 6-pin Slimline Serial ATA powerconnector. Note that pin 1 (devicepresent) is shorter than the others.

Pin # Function

13.3 V

2

3Ground

4

55 V

6

7 Reserved

8Vendor Specific

9

3.3 V lines unconnected. This precludes the use of such adapters with drives that require 3.3 V power.Understanding this, drive manufacturers have largely left the 3.3 V power lines unused.

Slimline connector

SATA 2.6 first defined the slimline connector, intended for smaller form-factors; e.g., notebook optical drives.

Micro connector

The micro connector originated with SATA 2.6. It is intended for 1.8-inch hard drives. There is also a micro dataconnector, which it is similar to the standard data connector but is slightly thinner.

TopologySATA uses a point-to-point architecture. The connection between the controllerand the storage device is direct.

Modern PC systems usually have a SATA controller on the motherboard, or



SATA topology: host –expansor - device

The official eSATA logo

installed in a PCI or PCI Express slot. Most SATA controllers have multipleSATA ports and can be connected to multiple storage devices. There are alsoport expanders or multipliers which allow multiple storage devices to beconnected to a single SATA controller port.

EncodingPhysical transmission uses a logic encoding known as 8b/10b encoding. Thisscheme eliminates the need to send a separate clock signal with the data stream. The stream itself containsnecessary synchronization information which allows for SATA host/drive to extract clocking. Use of 8b/10bencoding means the stream is also DC-balanced which allows the signals to be AC-coupled.

Separate point-to-point AC-coupled LVDS links are used for physical transmission between host and drive.

External SATAeSATA, standardized in 2004, provides a variant of SATA meant for externalconnectivity. It has revised electrical requirements in addition to incompatiblecables and connectors:

Minimum transmit potential increased: Range is 500–600 mV instead of400–600 mV.Minimum receive potential decreased: Range is 240–600 mV instead of325–600 mV.Identical protocol and logical signaling (link/transport-layer and above), allowing native SATA devices to bedeployed in external enclosures with minimal modificationMaximum cable length of 2 metres (6.6 ft) (USB and FireWire allow longer distances.)The external cable connector equates to a shielded version of the connector specified in SATA 1.0a withthese basic differences:

The external connector has no "L" shaped key, and the guide features are vertically offset and reducedin size. This prevents the use of unshielded internal cables in external applications and vice-versa.To prevent ESD damage, the design increased insertion depth from 5 mm to 6.6 mm and the contactsare mounted farther back in both the receptacle and plug.To provide EMI protection and meet FCC and CE emission requirements, the cable has an extralayer of shielding, and the connectors have metal contact-points.The connector shield has springs as retention features built in on both the top and bottom surfaces.The external connector and cable have a design-life of over five thousand insertions and removals,while the internal connector is only specified to withstand fifty.

Aimed at the consumer market, eSATA enters an external storage marketalready served by the USB and FireWire interfaces. Most external hard-disk-drive cases with FireWire or USB interfaces use either PATA or SATA drivesand "bridges" to translate between the drives' interfaces and the enclosures'external ports, and this bridging incurs some inefficiency. Some single disks cantransfer 131 MB/s during real use,[8] more than twice the maximum transfer rateof USB 2.0 or FireWire 400 (IEEE 1394a) and well in excess of the maximumtransfer rate of FireWire 800, though the S3200 FireWire 1394b spec reaches



SATA (left) and eSATA (right)connectors

HDMI, Ethernet, and eSATAports on a Sky+ HD Digibox

transfer rate of FireWire 800, though the S3200 FireWire 1394b spec reaches~400 MB/s (3.2 Gbit/s). Finally, some low-level drive features, such asS.M.A.R.T., may not operate through USB or FireWire bridging. eSATA doesnot suffer from these issues. USB 3.0's 4.8Gbit/s and Firewire's future 6.4Gbit/swill be faster than eSATA I, but the eSATA version of SATA III will operate at 6.0Gbit/s, thereby operating atnegligible differences of each other.[21]

eSATA can be differentiated from USB 2.0 and FireWire external storage forseveral reasons. As of early 2008, the vast majority of mass-market computershave USB ports and many computers and consumer electronic appliances haveFireWire ports, but few devices have external SATA connectors. For smallform-factor devices (such as external 2.5-inch disks), a PC-hosted USB orFireWire link supplies sufficient power to operate the device. Where a PC-hosted port is concerned, eSATA connectors cannot supply power, and wouldtherefore be more cumbersome to use[22].

Owners of desktop computers that lack a built-in eSATA interface can upgradethem with the installation of an eSATA host bus adapter (HBA), whilenotebooks can be upgraded with Cardbus[23] or ExpressCard[24] versions of an eSATA HBA. With passiveadapters the maximum cable length is reduced to 1 metre (3.3 ft) due to the absence of compliant eSATA signal-levels. Full SATA speed for external disks (115 MB/s) have been measured with external RAID enclosures.

Pre-standard implementationsPrior to the final eSATA specification, a number of products existed designed for external connections of SATAdrives. Some of these use the internal SATA connector or even connectors designed for other interfacespecifications, such as FireWire. These products are not eSATA compliant. The final eSATA specification featuresa specific connector designed for rough handling, similar to the regular SATA connector, but with reinforcements inboth the male and female sides, inspired by the USB connector. eSATA resists inadvertent unplugging, and canwithstand yanking or wiggling which would break a male SATA connector (the hard-drive or host adapter, usuallyfitted inside the computer). With an eSATA connector, considerably more force is needed to damage theconnector, and if it does break it is likely to be the female side, on the cable itself, which is relatively easy toreplace.

Backward and forward compatibility

SATA and PATA

At the device level, SATA and PATA (Parallel Advanced Technology Attachment) devices remain completelyincompatible—they cannot be interconnected. At the application level, SATA devices can be specified to look andact like PATA devices.[25] Many motherboards offer a "legacy mode" option which makes SATA drives appear tothe OS like PATA drives on a standard controller. This eases OS installation by not requiring a specific driver to beloaded during setup but sacrifices support for some features of SATA and generally disables some of the boards'PATA or SATA ports since the standard PATA controller interface only supports 4 drives. (Often which ports aredisabled is configurable.)

The common heritage of the ATA command set has enabled the proliferation of low-cost PATA to SATA bridge-chips. Bridge-chips were widely used on PATA drives (before the completion of native SATA drives) as well as



standalone "dongles." When attached to a PATA drive, a device-side dongle allows the PATA drive to function asa SATA drive. Host-side dongles allow a motherboard PATA port to function as a SATA host port.

The market has produced powered enclosures for both PATA and SATA drives which interface to the PC throughUSB, Firewire or eSATA, with the restrictions noted above. PCI cards with a SATA connector exist that allowSATA drives to connect to legacy systems without SATA connectors.

SATA 1.5 Gbit/s and SATA 3 Gbit/s

The designers of SATA aimed for backward and forward compatibility with future revisions of the SATAstandard.[26]

According to the hard drive manufacturer Maxtor, motherboard host controllers using the VIA and SIS chipsetsVT8237, VT8237R, VT6420, VT6421L, SIS760, SIS964 found on the ECS 755-A2 manufactured in 2003, donot support SATA 3 Gbit/s drives. Additionally, these host controllers do not support SATA 3 Gbit/s optical discdrives. To address interoperability problems, the largest hard drive manufacturer, Seagate/Maxtor, has added auser-accessible jumper-switch known as the Force 150, to switch between 150 MB/s and 300 MB/s operation.[27]

Users with a SATA 1.5 Gbit/s motherboard with one of the listed chipsets should either buy an ordinary SATA1.5 Gbit/s hard disk, buy a SATA 3 Gbit/s hard disk with the user-accessible jumper, or buy a PCI or PCI-E cardto add full SATA 3 Gbit/s capability and compatibility. Western Digital uses a jumper setting called OPT1 Enabledto force 150 MB/s data transfer speed. OPT1 is used by putting the jumper on pins 5 & 6.[28]

Comparisons with other interfaces

SATA and SCSI

SCSI currently offers transfer rates higher than SATA, but it uses a more complex bus, usually resulting in highermanufacturing costs. SCSI buses also allow connection of several drives (using multiple channels, 7 or 15 on eachchannel), whereas SATA allows one drive per channel, unless using a port multiplier.

SATA 3 Gbit/s offers a maximum bandwidth of 300 MB/s per device compared to SCSI with a maximum of320 MB/s. Also, SCSI drives provide greater sustained throughput than SATA drives because of disconnect-reconnect and aggregating performance. SATA devices generally link compatibly to SAS enclosures and adapters,while SCSI devices cannot be directly connected to a SATA bus.

SCSI, SAS and fibre-channel (FC) drives are typically more expensive so they are traditionally used in servers anddisk arrays where the added cost is justifiable. Inexpensive ATA and SATA drives evolved in the home-computermarket, hence there is a view that they are less reliable. As those two worlds overlapped, the subject of reliabilitybecame somewhat controversial. Note that, generally, the failure rate of a disk drive is related to the quality of itsheads, platters and supporting manufacturing processes, not to its interface.

SATA in comparison to other buses

Name Raw bandwidth(Mbit/s)

Transfer speed(MB/s) Max. cable length (m)

Powerprovided

Devices perChannel

eSATA 3,000 300 2 with eSATA HBA (1 withNo[29] 1 (15 with port



eSATA 3,000 300 passive adapter) No[29]multiplier)

SATA300 3,000 300 1 No 1 (15 with port

multiplier)

SATA150 1,500 150 1 No 1 per line

PATA133 1,064 133 0.46 (18 in) No 2

SAS 300 3,000 300 8 No 1 (16k withexpanders)

SAS 150 1,500 150 8 No 1 (16k withexpanders)

FireWire3200 3,144 393 100; alternate cables

available for >100 m15 W, 12–

25 V 63 (with hub)

FireWire800 786 98.25 100[30] 15 W, 12–

25 V 63 (with hub)

FireWire400 393 49.13 4.5[30][31] 15 W, 12–

25 V 63 (with hub)

USB 3.0* 4,800 600 3[32] 4.5 W, 5 V127 (withhub)[32]

USB 2.0 480 60 5[33] 2.5 W, 5 V 127 (with hub)

USB 1.0 12 1.5 3 Yes

Ultra-320SCSI 2,560 320 12 No 15 (plus the

HBA)

FibreChannel

over opticfiber

10,520 2,000 2–50,000 No126

(16,777,216with switches)

FibreChannel

overcoppercable

4,000 400 12 No126

(16,777,216with switches)

InfiniBand12×

Quad-rate120,000 12,000

5 (copper)[34][35]

<10,000 (fiber)No

1 with point topoint

Many withswitched fabric

* USB 3.0 specification released to hardware vendors 17 November 2008.

Unlike PATA, both SATA and eSATA support hot-swapping by design. However, this feature requires proper



mailto:@PXOWLSOLHU

support at the host, device (drive), and operating-system level. In general, all SATA devices (drives) support hot-swapping (due to the requirements on the device-side), but requisite support is less common on SATA hostadapters.[1]

SCSI-3 devices with SCA-2 connectors are designed for hot-swapping. Many server and RAID systems providehardware support for transparent hot-swapping. The designers of the SCSI standard prior to SCA-2 connectorsdid not target hot-swapping, but, in practice, most RAID implementations support hot-swapping of hard disks.

Serial Attached SCSI (SAS) is designed for hot-swapping.

See alsoAdvanced Host Controller Interface (AHCI)AT Attachment (ATA)FATANative Command Queuing (NCQ)TRIM (SSD command)Compare SATA BandwidthCompare eSATA BandwidthList of device bandwidthsList of computer standards

Notes and references

1. ^ a b http://ata.wiki.kernel.org/index.php/Software_status#Hotplug_support2. ^ Donald Melanson (2008-02-25). "CFast CompactFlash cards now said to be coming in "18 to 24 months"

(http://www.engadget.com/2008/02/25/cfast-compactflash-cards-now-said-to-be-coming-in-18-to-24-mont/) ".Engadget. http://www.engadget.com/2008/02/25/cfast-compactflash-cards-now-said-to-be-coming-in-18-to-24-mont/. Retrieved 2009-03-19.

3. ^ "Pretec release CFast card with SATA interface(http://www.dpreview.com/news/0901/09010902preteccfaststoragecards.asp) ". DPReview. 2009-01-08.http://www.dpreview.com/news/0901/09010902preteccfaststoragecards.asp. Retrieved 2009-03-19.

4. ^ "ATA-ATAPI.COM Serial ATA (SATA) (http://www.ata-atapi.com/sata.html) ". http://www.ata-atapi.com/sata.html. Retrieved 2009-01-29.

5. ^ Intel Matrix Storage Technology (http://www.intel.com/support/chipsets/imst/sb/CS-020825.htm) . IntelSupport.

6. ^ Microsoft Help and Support (http://support.microsoft.com/kb/922976)7. ^ Serial ATA (SATA) Linux hardware/driver status report (http://linux-ata.org/driver-status.html#ahci)8. ^ a b Patrick Schmid and Achim Roos (2009-04-21). "New Desktop Hard Drives: Speed Or Capacity?

(http://www.tomshardware.com/reviews/2tb-hdd-caviar,2261-7.html) ". tomshardware.com.http://www.tomshardware.com/reviews/2tb-hdd-caviar,2261-7.html. Retrieved 2009-08-07.

9. ^ Patrick Schmid and Achim Roos (2009-01-28). "Six New SSDs: Can Intel Be Dethroned? Throughput, InterfacePerformance (http://www.tomshardware.com/reviews/ssd-hdd-flash,2127-9.html) ". tomshardware.com.http://www.tomshardware.com/reviews/ssd-hdd-flash,2127-9.html. Retrieved 2009-03-15.

10. ^ Service and Support (http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1337)Western Digital.

11. ^ http://www.anandtech.com/storage/showdoc.aspx?i=2450 What's in a name? SATA II Misconceptions; June20th, 2005

12. ^ http://www.theinquirer.net/inquirer/news/1035081/there-is-no-such-thing-as-sata-ii-drives-stupid 27 January



200713. ^ SATA-IO (2008-08-18). "New SATA Spec Will Double Data Transfer Rates to 6 Gbit/s (http://www.sata-

io.org/documents/SATA_6gbphy_pressrls_finalrv2.pdf) " (PDF). Press release. http://www.sata-io.org/documents/SATA_6gbphy_pressrls_finalrv2.pdf. Retrieved 2009-07-13.

14. ^ [1] (http://www.sata-io.org/6gbdetails.asp)15. ^ Serial ATA International Organization (May 27, 2009). "SATA-IO Releases SATA Revision 3.0 Specification

(http://www.sata-io.org/documents/SATA-Revision-3.0-Press-Release-FINAL-052609.pdf) ". Press release.http://www.sata-io.org/documents/SATA-Revision-3.0-Press-Release-FINAL-052609.pdf. Retrieved 2009-07-03.

16. ^ The Inquirer - IDF Fall 2008 coverage (http://www.theinquirer.net/inquirer/news/1023995/idf-2008-sata-doubles-speed)

17. ^ EETimes news report(http://www.eetimes.com/news/latest/showArticle.jhtml;jsessionid=BPV3PTKDT0FC2QSNDLSCKHA?articleID=210101445)

18. ^ SATA-IO website (http://www.serialata.org/6gbnamingguidelines.asp)19. ^ http://www.serialata.org/developers/naming_guidelines.asp20. ^ http://techreport.com/discussions.x/1762421. ^ "Questions about the indicators of health/performance (in percent) (http://www.hddlife.com/eng/faq.html) ".

HDDlife. http://www.hddlife.com/eng/faq.html. Retrieved 2007-08-29.22. ^ "External Serial ATA (http://www.sata-io.org/documents/External%20SATA%20WP%2011-09.pdf) ". Silicon

Image, Inc. http://www.sata-io.org/documents/External%20SATA%20WP%2011-09.pdf. Retrieved 2009-08-08.23. ^ CardBus SATA adapter (http://www.addonics.com/products/host_controller/adcb2sa-e.asp)24. ^ ExpressCard SATA adapter (http://www.addonics.com/products/host_controller/adexc34-2e.asp)25. ^ "A comparison with Ultra ATA Technology (http://www.sata-io.org/documents/serialata%20-

%20a%20comparison%20with%20ultra%20ata%20technology.pdf) " (PDF). SATA-IO. http://www.sata-io.org/documents/serialata%20-%20a%20comparison%20with%20ultra%20ata%20technology.pdf. Retrieved2007-07-12.

26. ^ Serial ATA - Next Generation Storage Interface(http://www.hitachigst.com/hdd/technolo/SerialATA_white_paper.htm) Hitachi Global Storage Technologies.

27. ^ Barracuda 7200.9 SATA(http://web.archive.org/web/20071230220101/http://www.seagate.com/support/disc/sata/st3160812as.html)Seagate.

28. ^ (PDF) Jumper Settings Info Sheet (http://www.wdc.com/en/library/eide/2579-001037.pdf) . Western Digital.November 2005. http://www.wdc.com/en/library/eide/2579-001037.pdf. Retrieved 2009-07-03.

29. ^ SATA-IO states power will be added by 200930. ^ a b "FireWire Developer Note: FireWire Concepts

(http://developer.apple.com/documentation/HardwareDrivers/Conceptual/HWTech_FireWire/Articles/FireW_concepts.html) ". Apple Developer Connection.http://developer.apple.com/documentation/HardwareDrivers/Conceptual/HWTech_FireWire/Articles/FireW_concepts.html. Retrieved 2009-07-13.

31. ^ 16 cables can be daisy chained up to 72 m32. ^ a b Frenzel, Louis E. (September 25, 2008). "USB 3.0 Protocol Analyzer Jumpstarts 4.8-Gbit/s I/O Projects

(http://electronicdesign.com/Articles/ArticleID/19680/19680.html) ". Electronic Design.http://electronicdesign.com/Articles/ArticleID/19680/19680.html. Retrieved 2009-07-03.

33. ^ USB hubs can be daisy chained up to 25 m34. ^ Minich, Makia (2007-06-25). "Infiniband Based Cable Comparison

(http://download.intel.com/design/network/products/optical/cables/ornl.pdf) " (PDF).http://download.intel.com/design/network/products/optical/cables/ornl.pdf. Retrieved 2008-02-11.

35. ^ Feldman, Michael (2007-07-17). "Optical Cables Light Up InfiniBand(http://www.hpcwire.com/hpc/1729056.html) ". HPCwire (Tabor Publications & Events): p. 1.http://www.hpcwire.com/hpc/1729056.html. Retrieved 2008-02-11.



External linksSerial ATA International Organization (SATA-IO) (http://www.sata-io.org/)EETimes Serial ATA and the evolution in data storage technology, Mohamed A. Salem(http://www.edadesignline.com/howto/207402359)"SATA-1" specification, as a zipped pdf; Serial ATA: High Speed Serialized AT Attachment, Revision 1.0a,7-January-2003 (http://www.sata-io.org/documents/serialata10a.zip) .Errata and Engineering Change Notices to above "SATA-1" specification, as a zip of pdfs(http://web.archive.org/web/20070928100150/http://www.sata-io.org/docs/10a_ECN.zip)Dispelling the Confusion: SATA II does not mean 3 Gbit/s (https://sata-io.org/developers/naming_guidelines.asp)SATA-IO White Paper - External SATA (eSATA) (http://www.sata-io.org/documents/External%20SATA%20WP%2011-09.pdf) PDF (502 kiB)SATA motherboard connector pinout (http://pinouts.ru/HD/serialATA_pinout.shtml)AHCI/RAID Intel Matrix Storage Technology: Unattended installation instructions under Windows XP(http://www.intel.com/support/chipsets/imst/sb/CS-020825.htm)Intel Matrix Storage Manager: How do I install an operating system on single serial ATA hard drive?(http://support.intel.com/support/chipsets/imsm/sb/CS-021736.htm)Serial ATA Connector Schematic and Pinout(http://www.allpinouts.org/index.php/Serial_ATA_(SATA,_Serial_Advanced_Technology_Attachment))Serial ATA server and storage use cases (http://www.serialata.org/documents/SATA_illus_guide_final.pdf)How to Install and Troubleshoot SATA Hard Drives (http://www.seagate.com/ww/v/index.jsp?locale=en-US&name=install-troubleshoot-sata-non-mac&vgnextoid=2b089d2c3c90e010VgnVCM100000dd04090aRCRD)Serial ATA and the 7 Deadly Sins of Parallel ATA (http://www.lostcircuits.com/mambo//index.php?option=com_content&task=view&id=50&Itemid=46&limit=1&limitstart=0)Everything You Need to Know About Serial ATA (http://www.hardwaresecrets.com/article/27)Straightforward diagram comparing SATA and ATA/IDE hard drive interfaces(http://www.laptopparts101.com/hard-drive/)

Retrieved from "http://en.wikipedia.org/wiki/Serial_ATA"Categories: Serial ATA | Computer buses | 2003 introductions

This page was last modified on 6 November 2009 at 20:03.Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply.See Terms of Use for details.Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.



Documents

Serial ATA - Wikipedia, The Free Encyclopedia