Serial ATA

SATA
Serial ATA
}}
First-generation (1.5 Gbit/s) SATA ports on a motherboard
Year created 2003
Supersedes Parallel ATA (PATA)
Capacity 1.5, 3.0, 6.0 Gbit/s
Style Serial
Hotplugging interface Yes[1]
External interface Yes (eSATA)

Serial ATA (SATA or Serial Advanced Technology Attachment) is a computer bus interface for connecting host bus adapters to mass storage devices such as hard disk drives and optical drives. Serial ATA was designed to replace the older ATA (AT Attachment) standard (also known as EIDE). It is able to use the same low level commands, but serial ATA host-adapters and devices communicate via a high-speed serial cable over two pairs of conductors. In contrast, the parallel ATA (the redesignation for the legacy ATA specifications) used 16 data conductors each operating at a much lower speed.

SATA offers several advantages over the older parallel ATA (PATA) interface: reduced cable-bulk and cost (reduced from 80 wires to seven), faster and more efficient data transfer, and hot swapping.

The SATA host adapter is integrated into almost all modern consumer laptop computers and desktop motherboards. As of 2009, SATA has replaced parallel ATA in most shipping consumer PCs. PATA remains in industrial and embedded applications dependent on CompactFlash storage although the new CFast storage standard will be based on SATA.[2][3]

Contents

SATA specification bodies

Serial ATA industry compatibility specifications originate from The Serial ATA International Organization (aka. SATA-IO, serialata.org). The SATA-IO group collaboratively creates, reviews, ratifies, and publishes the interoperability specifications, the test cases, and plug-fests. As with many other industry compatibility standards, the SATA content ownership is transferred to other industry bodies: primarily the INCITS T13subcommittee ATA, the INCITS T10 subcommittee (SCSI); a subgroup of T10 responsible for SAS. The complete specification from SATA-IO.[4] The remainder of this article will try to use the terminology and specifications of SATA-IO.

The SATA-IO succeeded in its mission of improving PATA. More than 1.1 billion SATA disk drives have been shipped from 2001 through 2008. SATA’s market share in the desktop PC market is 99% in 2008. http://www.serialata.org/documents/SATA-Rev-30-Presentation.pdf

Features

Hotplug

The Serial ATA Spec, includes logic for SATA device hotplugging. Devices and motherboards that meet the interoperability spec are capable of hot plugging.

Advanced Host Controller Interface

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

Windows device drivers that are labeled as SATA are often running in IDE emulation mode unless they explicitly state that they are AHCI mode, in RAID mode, or a mode provided by a proprietary driver and command set that was designed to allow access to SATA's advanced features before AHCI became popular. Modern versions of Microsoft Windows, FreeBSD, Linux with version 2.6.19 onward,[5] as well as Solaris and OpenSolaris include support for AHCI, but older OSes such as Windows XP do not. Even in those instances a proprietary driver may have been created for a specific chipset, such as Intel's.[6]

Revisions

SATA Revision 1.0 (SATA 1.5 Gbit/s)

First-generation SATA interfaces, now known as SATA 1.5 Gbit/s, communicate at a rate of 1.5 Gbit/s. Taking 8b/10b encoding overhead into account, they have an actual uncoded transfer rate of 1.2 Gbit/s (1500000000*8/10/1024/1024/8 ≅ 143.05 MiB/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 mechanical hard disk drives can transfer data at up to 157 MB/s,[7] which is beyond the capabilities of the older PATA/133 specification and also exceeds a SATA 1.5 Gbit/s link. High-performance flash drives can transfer data at up to 308 MB/s which exceeds a SATA 3 Gbit/s link.[8]

SATA Revision 2.0 (SATA 3 Gb/s)

Second generation SATA interfaces running at 3.0 Gbit/s are shipping in high volume as of 2010, and prevalent in all SATA disk drives and the majority of PC and server chipsets. 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 (286 MiB/s). The theoretical burst throughput of SATA 3.0 Gbit/s is roughly double that of PATA/133. In addition, SATA devices offer enhancements such as NCQ that improve performance in a multitasking environment.

All SATA data cables meeting the SATA spec are rated for 3.0 Gbit/s and 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, and this is being addressed with the SATA 6 Gb/s interoperability standard.

SATA Revision 3.0 (SATA 6 Gb/s)

Serial ATA International Organization presented the draft specification of SATA 6 Gbit/s physical layer in July 2008,[9] and ratified its physical layer specification on August 18, 2008.[10] The full 3.0 standard (peak throughput about 600 MB/s (10b/8b coding plus 8 bit to one byte, without the protocol, or encoding overhead) was released on May 27, 2009.[11] While even the fastest conventional hard disk drives can barely saturate the original SATA 1.5 Gbit/s bandwidth, Solid-State Drives have already saturated the SATA 3 Gbit/s limit at 250 MB/s net read speed. Ten channels of fast flash can reach well over 500 MB/s with new ONFI drives, so a move from SATA 3 Gbit/s to SATA 6 Gbit/s would benefit the flash read speeds. As for the standard hard disks, the reads from their built-in DRAM cache will end up faster across the new interface.[12] SATA 6 Gbit/s hard drives and Motherboards are now shipping from several suppliers.

The new specification contains the following changes:

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 a meter. The new speeds may require higher power consumption for supporting chips, factors that new process technologies and power management techniques are expected to mitigate. The new specification can use existing SATA cables and connectors, although some OEMs are expected to upgrade host connectors for the higher speeds.[13] Also, the new standard is backwards compatible with SATA 3 Gbit/s.[14]

eSATA

An eSATAp port (left) and an eSATA port (right)
The official eSATA logo

Standardized in 2004, eSATA (e=external) provides a variant of SATA meant for external connectivity. It has revised electrical requirements in addition to incompatible cables and connectors:

SATA (left) and eSATA (right) connectors

Aimed at the consumer market, eSATA enters an external storage market already served by the USB and FireWire interfaces. Most external hard-disk-drive cases with FireWire or USB interfaces use either PATA or SATA drives and "bridges" to translate between the drives' interfaces and the enclosures' external ports, and this bridging incurs some inefficiency. Some single disks can transfer 157 MB/s during real use,[7] about four times the maximum transfer rate of USB 2.0 or FireWire 400 (IEEE 1394a) and almost twice as fast as the maximum 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 as S.M.A.R.T., may not operate through some USB [2] or FireWire or USB+FireWire bridges. eSATA does not suffer from these issues provided that the controller manufacturer (and its drivers) presents eSATA drives as ATA devices, rather than as "SCSI" devices (as has been common with Silicon Image, JMicron, and NVIDIA nForce drivers for Windows Vista); In those cases, even SATA drives will not have low-level features accessible. USB 3.0's 4.8 Gbit/s and Firewire's future 6.4 Gb/s (768 MB/s) will be faster than eSATA I, but the eSATA version of SATA 6G will operate at 6.0 Gb/s (the term SATA III is being eschewed by the SATA-IO to avoid confusion with SATA II 3.0 Gb/s, which was colloquially referred to as "SATA 3G" [bps] or "SATA 300" [MB/s] since 1.5 Gb/s SATA I and 1.5 Gb/s SATA II were referred to as both "SATA 1.5G" [b/s] or "SATA 150" [MB/s]). Therefore, they will operate at negligible differences of each other [15].

HDMI, Ethernet, and eSATA ports on a Sky+ HD Digibox, which allows for extended external DVR storage.

eSATA can be differentiated from USB 2.0 and FireWire external storage for several reasons. As of early 2008, the vast majority of mass-market computers have USB ports and many computers and consumer electronic appliances have FireWire ports, but few devices have external SATA connectors. For small form-factor devices (such as external 2.5-inch disks), a PC-hosted USB or FireWire link supplies sufficient power to operate the device. Where a PC-hosted port is concerned, eSATA connectors cannot supply power, and would therefore be more cumbersome to use. Note that this problem has been solved by the introduction of eSATAp.[16] Some e-sata ports double as eSATA/USB.

Owners of desktop computers that lack a built-in eSATA interface can upgrade them with the installation of an eSATA host bus adapter (HBA), while notebooks can be upgraded with Cardbus[17] or ExpressCard[18] versions of an eSATA HBA. With passive adapters, 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.

eSATAp

1 cable solution. An eSATAp HDD enclosure from Delock.

eSATAp is also known as Power over eSATA or eSATA/USB Combo. eSATAp port combines the strength of both eSATA(high speed) and USB(compatibility) into a single port. eSATAp devices are now capable of being self powered. On a desktop workstation, eSATAp port can supply 12 V to power up a 3.5" hard disk drive (HDD) or a 5.25" DVD-RW without needing separate power source as compared to eSATA and USB 2. On a notebook eSATAp port can supply 5 V to power up a 2.5" HDD/SSD as compared to eSATA. Many notebooks are now equipped with this combo port. A list of notebooks with this new port is available here [3]

eSATAp can be implemented in all machines with a spare SATA port. These machines include PC notebooks, desktops, Apple Mac Pro, and Linux or Unix servers. This makes eSATAp an easy, economical, cross platform solution for external storage.

Pre-standard implementations

Terminology

The name SATA II has become synonymous with the 3 Gbit/s standard. In order to provide the industry with consistent terminology, the SATA-IO has compiled a set of marketing guidelines for the third revision of the specification.

Using the terms SATA III or SATA 3.0 to refer to a SATA 6 Gb/s product, is unclear and not preferred. SATA-IO has provided a guideline to foster consistent marketing terminology across the industry.[20]

Cables, connectors, and ports

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 SATA hard disks for desktop and server computers and 2.5-inch disks for portable or small computers; this allows 2.5-inch 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.[21]

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

Data

Pin # Function
1 Ground
2 A+ (transmit)
3 A− (transmit)
4 Ground
5 B− (receive)
6 B+ (receive)
7 Ground
8 Coding notch
A 7-pin Serial ATA data cable.
A 7-pin Serial ATA right-angle data cable.

The SATA standard defines a data cable with seven conductors (3 grounds and 4 active data lines in two pairs) and 8 mm wide wafer connectors on each end. SATA cables can have lengths up to 1 metre (3.3 ft), and connect one motherboard socket to one hard drive. PATA ribbon cables, in comparison, connect one motherboard socket to up to two hard drives, carry either 40 or 80 wires, and are limited to 45 centimetres (18 in) in length by the PATA specification (however, cables up to 90 centimetres (35 in) are readily available). Thus, SATA connectors and cables are easier to fit in closed spaces and reduce obstructions to air cooling. They are more susceptible to accidental unplugging and breakage than PATA, but cables can be purchased that have a locking feature, whereby a small (usually metal) spring holds the plug in the socket.

One of the problems associated with the transmission of data at high speed over electrical connections is loosely described as noise. Despite attempts to avoid it, some electrical coupling will exist both between data circuits and between them and other circuits. As a result, the data circuits can both affect other circuits, whether they are within the same piece of equipment or not, and be affected by them. Designers use a number of techniques to reduce the undesirable effects of such unintentional coupling. One such technique used in SATA links is differential signaling. This is an enhancement over PATA, which uses single-ended signaling.

Power supply

Standard 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
A 15-pin Serial ATA power connector.
A 15-pin Serial ATA power receptacle.
This connector does not provide the extended
pins 4 and 12 needed for hot-plugging.[22]

The SATA standard specifies a different power connector than the decades-old four-pin Molex connector found on pre-SATA devices. Like the data cable, it is wafer-based, but its wider 15-pin shape prevents accidental mis-identification and forced insertion of the wrong connector type. Native SATA devices favor the SATA power-connector, although some early SATA drives retained older 4-pin Molex in addition to the SATA power connector.

SATA features more pins than the traditional connector for several reasons:

Adapters that can convert a 4-pin Molex connector to a SATA power connector exist. 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 3.3 V lines unconnected. This precludes the use of such adapters with drives that require 3.3 V power. Some 4-pin Molex to SATA power connectors have electronics included in the connector to also provide the 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.

Pin # Function
1 Device presence
2 5 V
3
4 Manufacturing diagnostic
5 Ground
6
A 6-pin Slimline Serial ATA power connector. Note that pin 1 (device presence) is shorter than the others.

Micro connector

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

Pin # Function
1 3.3 V
2
3 Ground
4
5 5 V
6
7 Reserved
8 Vendor specific
9

Protocol

Topology

SATA topology: host – expansor - device

SATA uses a point-to-point architecture. The connection between the controller and the storage device is direct.

Modern PC systems usually have a SATA controller on the motherboard, or installed in a PCI or PCI Express slot. Most SATA controllers have multiple SATA ports and can be connected to multiple storage devices. There are also port expanders or multipliers that allow multiple storage devices to be connected to a single SATA controller port.

Encoding

Physical transmission uses a logic encoding known as 8b/10b encoding. This scheme eliminates the need to send a separate clock signal with the data stream. The stream itself contains necessary synchronization information that allows for SATA host/drive to extract clocking. Use of 8b/10b encoding 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.

Backward and forward compatibility

SATA and PATA

At the device level, SATA and PATA (Parallel AT Attachment) devices remain completely incompatible—they cannot be interconnected. At the application level, SATA devices can be specified to look and act like PATA devices.[23] Many motherboards offer a "legacy mode" option, which makes SATA drives appear to the OS, like PATA drives on a standard controller. This eases OS installation by not requiring a specific driver to be loaded during setup but sacrifices support for some features of SATA and, in general, disables some of the boards' PATA or SATA ports, since the standard PATA controller interface supports only 4 drives. (Often which ports are disabled 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 as a 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 that interface to the PC through USB, Firewire or eSATA, with the restrictions noted above. PCI cards with a SATA connector exist that allow SATA drives to connect to legacy systems without SATA connectors.

SATA 1.5 Gbit/s, SATA 3 Gbit/s and SATA 6 Gbit/s

The designers of SATA aimed for backward and forward compatibility with future revisions of the SATA standard.[24]

Comparisons with other interfaces

SATA and SCSI

SCSI uses a more complex bus, usually resulting in higher manufacturing costs. SCSI buses also allow connection of several drives (using multiple channels, 7 or 15 on each channel), 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 of 320 MB/s. Also, SCSI drives provide greater sustained throughput than SATA drives because of disconnect-reconnect and aggregating performance. In general, SATA devices link compatibly to SAS enclosures and adapters, whereas 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 and disk arrays where the added cost is justifiable. Inexpensive ATA and SATA drives evolved in the home-computer market, hence there is a view that they are less reliable. As those two worlds overlapped, the subject of reliability became somewhat controversial. Note that, in general, the failure rate of a disk drive is related to the quality of its heads, platters and supporting manufacturing processes, not to its interface.

Serial ATA in the Enterprise has increased from 21.6% in 2006 to 27.6% in 2008. http://www.serialata.org/documents/SATA-Rev-30-Presentation.pdf

SATA in comparison to other buses

Name Raw bandwidth (Mbit/s) Transfer speed (MByte/s) Max. cable length (m) Power provided Devices per Channel
eSATA 3,000 300[25] 2 with eSATA HBA (1 with passive adapter) No 1 (15 with port multiplier)
eSATAp 5 V/12 V[26]
SATA 600 6,000 600[25] 1 No
SATA 300 3,000 300[25]
SATA 150 1,500 150[25] 1 per line
PATA 133 1,064 133.5 0.46 (18 in) No 2
SAS 600 6,000 600[25] 10 No 1 (>65k with expanders)
SAS 300 3,000 300[25]
SAS 150 1,500 150[25]
FireWire 3200 3,144 393 100 (more with special cables) 15 W, 12–25 V 63 (with hub)
FireWire 800 786 98.25 100[27]
FireWire 400 393 49.13 4.5[27][28]
USB 3.0* 4,000 400[25] 3[29] 4.5 W, 5 V 127 (with hub)[29]
USB 2.0 480 60 5[30] 2.5 W, 5 V
USB 1.0 12 1.5 3 Yes
SCSI Ultra-320 2,560 320 12 No 15 (plus the HBA)
Fibre Channel
over optic fiber
10,520 2,000 2–50,000 No 126
(16,777,216 with switches)
Fibre Channel
over copper cable
4,000 400 12
InfiniBand
Quad Rate
10,000 1,000 5 (copper)[31][32]

<10,000 (fiber)

No 1 with point to point
Many with switched fabric
Light Peak 10,000 1,250 100 No Many
* 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 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), also most SATA host adapters support this command.[1]

SCSI-3 devices with SCA-2 connectors are designed for hot-swapping. Many server and RAID systems provide hardware support for transparent hot-swapping. The designers of the SCSI standard prior to SCA-2 connectors did 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.

Development tools

When developing and/or troubleshooting the Serial ATA bus, examination of hardware signals can be very important to find problems. Logic analyzers and bus analyzers are tools which collect, analyze, decode, store signals so people can view the high-speed waveforms at their leisure.

See also

Notes and references

  1. 1.0 1.1 "Software status - ata Wiki". Ata.wiki.kernel.org. 2008-08-17. http://ata.wiki.kernel.org/index.php/Software_status#Hotplug_support. Retrieved 2010-01-26. 
  2. Donald Melanson (25 February 2008). "CFast CompactFlash cards now said to be coming in "18 to 24 months"". Engadget. http://www.engadget.com/2008/02/25/cfast-compactflash-cards-now-said-to-be-coming-in-18-to-24-mont/. Retrieved 19 March 2009. 
  3. "Pretec release CFast card with SATA interface". DPReview. 8 January 2009. http://www.dpreview.com/news/0901/09010902preteccfaststoragecards.asp. Retrieved 19 March 2009. 
  4. "ATA-ATAPI.COM Serial ATA (SATA)". http://www.ata-atapi.com/sata.html. Retrieved 29 January 2009. 
  5. "Serial ATA (SATA) Linux hardware/driver status report". Linux-ata.org. http://linux-ata.org/driver-status.html#ahci. Retrieved 2010-01-26. 
  6. http://www.intel.com/support/chipsets/imst/sb/CS-020825.htm
  7. 7.0 7.1 Patrick Schmid and Achim Roos (2010-04-06). "VelociRaptor Returns: 6Gb/s, 600GB, And 10,000 RPM". tomshardware.com. http://www.tomshardware.com/reviews/wd6000hlhx-velociraptor-600gb,2600-5.html. Retrieved 2010-06-26. 
  8. Patrick Schmid and Achim Roos (2010-04-13). "Spring 2010 Solid State Drive Roundup, Part 2". tomshardware.com. http://www.tomshardware.com/reviews/6gb-s-ssd-hdd,2603-7.html. Retrieved 2010-06-26. 
  9. SATA-IO (18 August 2008). "New SATA Spec Will Double Data Transfer Rates to 6 Gbit/s" (PDF). Press release. http://www.sata-io.org/documents/SATA_6gbphy_pressrls_finalrv2.pdf. Retrieved 13 July 2009. 
  10. "SATA Revision 3.0". SATA-IO. 27 May 2009. http://www.sata-io.org/technology/6Gbdetails.asp. Retrieved 4 December 2009. 
  11. Serial ATA International Organization (May 27, 2009). "SATA-IO Releases SATA Revision 3.0 Specification". Press release. http://www.sata-io.org/documents/SATA-Revision-3.0-Press-Release-FINAL-052609.pdf. Retrieved 3 July 2009. 
  12. "IDF Fall 2008 coverage". The Inquirer. http://www.theinquirer.net/inquirer/news/1023995/idf-2008-sata-doubles-speed. Retrieved 2010-01-26. 
  13. "EETimes news report". Eetimes.com. http://www.eetimes.com/news/latest/showArticle.jhtml;jsessionid=BPV3PTKDT0FC2QSNDLSCKHA?articleID=210101445. Retrieved 2010-01-26. 
  14. "SATA-IO Specifications and Naming Conventions". Sata-io.org. http://www.sata-io.org/developers/naming_guidelines.asp. Retrieved 2010-01-26. 
  15. "Questions about the indicators of health/performance (in percent)". HDDlife. http://www.hddlife.com/eng/faq.html. Retrieved 29 August 2007. 
  16. "External Serial ATA". Silicon Image, Inc. http://www.sata-io.org/documents/External%20SATA%20WP%2011-09.pdf. Retrieved 8 August 2009. 
  17. "CardBus SATA adapter". Addonics.com. http://www.addonics.com/products/host_controller/adcb2sa-e.asp. Retrieved 2010-01-26. 
  18. "ExpressCard SATA adapter". Addonics.com. http://www.addonics.com/products/host_controller/adexc34-2e.asp. Retrieved 2010-01-26. 
  19. [1]
  20. http://www.serialata.org/developers/naming_guidelines.asp
  21. "Get ready for mini-SATA". The Tech Report. 2009-09-21. http://techreport.com/discussions.x/17624. Retrieved 2010-01-26. 
  22. https://raid.wiki.kernel.org/index.php/Hardware_issues#Hotplug_support_by_SATA.2FSAS_cables
  23. "A comparison with Ultra ATA Technology" (PDF). SATA-IO. http://www.sata-io.org/documents/serialata%20-%20a%20comparison%20with%20ultra%20ata%20technology.pdf. Retrieved 12 July 2007. 
  24. Serial ATA - Next Generation Storage Interface Hitachi Global Storage Technologies.
  25. 25.0 25.1 25.2 25.3 25.4 25.5 25.6 25.7 "Technologies That Use 8b/10b Encoding". http://en.wikipedia.org/wiki/8b/10b_encoding. 
  26. "eSATAp Application". Delock.de. http://www.delock.de/mail/esatap/esatap.html. Retrieved 2010-01-26. 
  27. 27.0 27.1 "FireWire Developer Note: FireWire Concepts". Apple Developer Connection. http://developer.apple.com/documentation/HardwareDrivers/Conceptual/HWTech_FireWire/Articles/FireW_concepts.html. Retrieved 13 July 2009. 
  28. 16 cables can be daisy chained up to 72 m
  29. 29.0 29.1 Frenzel, Louis E. (September 25, 2008). "USB 3.0 Protocol Analyzer Jumpstarts 4.8-Gbit/s I/O Projects". Electronic Design. http://electronicdesign.com/Articles/ArticleID/19680/19680.html. Retrieved 3 July 2009. 
  30. USB hubs can be daisy chained up to 25 m
  31. Minich, Makia (25 June 2007). "Infiniband Based Cable Comparison" (PDF). http://download.intel.com/design/network/products/optical/cables/ornl.pdf. Retrieved 11 February 2008. 
  32. Feldman, Michael (17 July 2007). "Optical Cables Light Up InfiniBand". HPCwire (Tabor Publications & Events): p. 1. http://www.hpcwire.com/hpc/1729056.html. Retrieved 11 February 2008. 

External links