| SATA Serial ATA |
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First generation (1. 5 Gbit/s) SATA ports on a motherboard |
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| Year created: | 2003 |
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| Number of devices: | 1 |
| Capacity | 1. A motherboard is the central or primary Printed circuit board (PCB making up a complex electronic system such as a modern Computer or Laptop 5 Gbit/s, 3. 0 Gbit/s |
| Style: | Serial |
| Hotplugging? | Yes |
| External? | Yes, with eSATA |
Serial Advanced Technology Attachment (SATA, IPA: /ˈseɪtə/, /ˈsætə/ or 'sɑːtə) is a computer bus primarily designed for transfer of data between a computer and mass storage devices such as hard disk drives and optical drives. In Telecommunication and Computer science, serial communication is the process of sending data one Bit at one time sequentially over a Communication In Computer architecture, a bus is a subsystem that transfers data between computer components inside a Computer or between computers In Computing, mass storage refers to the storage of large amounts of information in a persisting and Machine-readable fashion A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device In Computing, an optical disc drive ( ODD) is a Disk drive that uses Laser light or electromagnetic waves near the Light spectrum
The main advantages over the older parallel ATA interface are faster data transfer, ability to remove or add devices while operating (hot swapping), thinner cables that let air cooling work more efficiently, and more reliable operation with tighter data integrity checks. AT Attachment with Packet Interface ( ATA/ATAPI) is a standard interface used to connect storage devices such as Hard disks Solid-state Data transmission is the transfer of Data from point-to-point often represented as an Electro-magnetic Signal over a physical point-to-point or point-to-multipoint Hot swapping and hot plugging are terms used to separately describe the functions of replacing system components hot swapping describes changing components like fans and
It was designed as a successor to the Advanced Technology Attachment standard (ATA), and is expected to eventually replace the older technology (retroactively renamed Parallel ATA or PATA). AT Attachment with Packet Interface ( ATA/ATAPI) is a standard interface used to connect storage devices such as Hard disks Solid-state A retronym is a type of Neologism coined for an old object or concept whose original name has come to be used for something else is no longer unique or is otherwise inappropriate Serial ATA adapters and devices communicate over a high-speed serial cable. In Telecommunication and Computer science, serial communication is the process of sending data one Bit at one time sequentially over a Communication
Contents |
The standard interface for SATA controllers is Advanced Host Controller Interface (AHCI), which allows advanced features of SATA such as hot plug and Native Command Queuing (NCQ). The Advanced Host Controller Interface ( AHCI) is a hardware mechanism that allows software to communicate with Serial ATA (SATA devices (such as host bus adapters The Advanced Host Controller Interface ( AHCI) is a hardware mechanism that allows software to communicate with Serial ATA (SATA devices (such as host bus adapters Hot swapping and hot plugging are terms used to separately describe the functions of replacing system components hot swapping describes changing components like fans and Native Command Queuing (NCQ is a technology designed to increase performance of SATA Hard disks under certain situations by allowing the individual hard disk to internally 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 that are not supported by the ATA/IDE standard. Windows device drivers that are labeled as SATA are usually running in IDE emulation mode unless they explicitly state that they are AHCI. While the drivers included with Windows XP do not support AHCI, AHCI has been implemented by proprietary device drivers. Windows XP is a family of 32-bit and 64-bit Operating systems produced by Microsoft for use on Personal computers including home and [1] Windows Vista and the current versions of Mac OS X and Linux [1] have native support for AHCI. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Linux (commonly pronounced ˈlɪnəks
The current SATA specification can support data transfer rates as high as 3. 0 Gbit/s per device. SATA uses only 4 signal lines; cables are more compact and cheaper than for PATA. SATA supports hot-swapping and NCQ. Hot swapping and hot plugging are terms used to separately describe the functions of replacing system components hot swapping describes changing components like fans and Native Command Queuing (NCQ is a technology designed to increase performance of SATA Hard disks under certain situations by allowing the individual hard disk to internally 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 Serial Attached SCSI (SAS) controllers and communicate on the same physical cable as native SAS disks, but SATA controllers cannot handle SAS disks. Introduction A typical Serial Attached SCSI system consists of the following basic components An Initiator is a device that originates device service
First-generation SATA interfaces, also known as SATA/150 or unofficially as SATA 1, communicate at a rate of 1. 5 gigabits per second (Gbit/s). In telecommunications Bit rate or Data transfer rate is the average number of Bits characters or blocks per unit time passing between equipment in a data transmission A gigabit is a unit of information or computer storage abbreviated Gbit (or Gb) Taking into account 8b10b coding overhead, the actual uncoded transfer-rate is 1. In Telecommunications 8b/10b is a Line code that maps 8-bit symbols to 10-bit symbols to achieve DC-balance (see 2 Gbit/s, or 1,200 megabits per second (Mbit/s). In telecommunications Bit rate or Data transfer rate is the average number of Bits characters or blocks per unit time passing between equipment in a data transmission A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) The theoretical burst throughput of SATA/150 is similar to that of PATA/133, but newer SATA devices offer enhancements such as NCQ which improve performance in a multitasking environment. AT Attachment with Packet Interface ( ATA/ATAPI) is a standard interface used to connect storage devices such as Hard disks Solid-state Native Command Queuing (NCQ is a technology designed to increase performance of SATA Hard disks under certain situations by allowing the individual hard disk to internally Data transfer rates are limited by mechanical hard drives themselves, not the interfaces: the fastest modern desktop hard drives transfer data at a maximum of about 120 MB/s,[2] which is well within the capabilities of even the older PATA/133 specification. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device A megabyte is a unit of Information or Computer storage equal to either 106 (1000000 Bytes or 220 (1048576 bytes depending on
During the initial period after SATA/150'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 generally perform identically to their PATA equivalents. Most lack support for some SATA-specific features such as NCQ. Native Command Queuing (NCQ is a technology designed to increase performance of SATA Hard disks under certain situations by allowing the individual hard disk to internally Bridged products gradually gave way to native SATA products.
Soon after SATA/150's introduction a number of shortcomings were observed. At the application level SATA could only handle one pending transaction at a time, like PATA; the SCSI interface has long been able to accept multiple outstanding requests and service them in the order which minimizes response time. This feature, Native Command Queuing (NCQ), was adopted as an optional supported feature for SATA 1. Native Command Queuing (NCQ is a technology designed to increase performance of SATA Hard disks under certain situations by allowing the individual hard disk to internally 5 Gbit/s and SATA 3. 0 Gbit/s devices.
First-generation SATA devices were at best little faster than parallel ATA/133 devices. A 3 Gbit/s signaling rate was added to the Physical layer (PHY layer), effectively doubling maximum data throughput from 150 MB/s to 300 MB/s. The Physical Layer is the first level in the seven-layer OSI model of computer networking. In Communication networks, such as Ethernet or Packet radio, throughput is the average rate of successful message delivery over a communication channel SATA/300's transfer rate is expected to satisfy drive throughput requirements for some time, as the fastest desktop hard disks barely saturate a SATA/150 link. A SATA data cable rated for 1. 5 Gbit/s will handle current second-generation SATA 3. 0 Gbit/s drives without any loss of sustained and burst data transfer performance.
Backward compatibility between SATA 1. 5 Gbit/s controllers and SATA 3. 0 Gbit/s devices was important, so SATA/300's autonegotiation sequence is designed to fall back to SATA/150 speed (1. 5 Gbit/s rate) when in communication with such devices. In practice, some older SATA controllers do not properly implement SATA speed negotiation. Affected systems require the user to set the SATA 3. 0 Gbit/s peripherals to 1. 5 Gbit/s mode, generally through the use of a jumper. [3] Chipsets known to have this fault include the VIA VT8237 and VT8237R south bridges, and the VIA VT6420 and VT6421L standalone SATA controllers. The Southbridge, also known as the I/O Controller Hub ( ICH) in Intel systems (AMD VIA SiS and others usually [4] SiS's 760 and 964 chipsets also initially exhibited this problem, though it can be rectified with an updated SATA controller ROM.
This table shows the real speed of SATA 1. 5 Gbit/s and SATA 3 Gbit/s (note the bottom row shows megabytes per second (MB/s, not Mbit/s):
| SATA 1. 5 Gbit/s | SATA 3 Gbit/s | |
|---|---|---|
| Frequency | 1500 MHz | 3000 MHz |
| Bits/clock | 1 | 1 |
| 8b10b encoding | 80% | 80% |
| bits/Byte | 8 | 8 |
| Real speed | 150 MB/s | 300 MB/s |
The 3. 0 Gbit/s specification has been widely referred to as "Serial ATA II" ("SATA II" or "SATA2"), contrary to the wishes of the Serial ATA International Organization (SATA-IO) which defines the standard. SATA II was originally 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, the name SATA II became synonymous with the 3 Gbit/s standard, so the group has since changed names to the Serial ATA International Organization, or SATA-IO, to avoid further confusion.
SATA's roadmap includes plans for a 6. 0 Gbit/s standard. In current PCs, SATA 3. 0 Gbit/s already greatly exceeds the sustainable (non-burst) transfer rate of even the fastest hard disks. The 6. 0 Gbit/s standard is useful right now in combination with port multipliers, which allow multiple drives to be connected to a single Serial ATA port, thus sharing the port's bandwidth with multiple drives. A Serial ATA port multiplier is a device that allows one to connect multiple SATA devices to a single SATA host port in a similar manner to that of a USB hub. [5] Solid-state drives may also one day make use of the faster transfer rate. A solid-state drive ( SSD) is a Data storage device that uses solid-state memory to store persistent Data.
Connectors and cables are the most visible difference between SATA and Parallel ATA drives. Unlike PATA, the same connectors are used on 3. 5-in (90 mm) SATA hard disks for desktop and server computers and 2. 5-in (70 mm) disks for portable or small computers; this allows 2. 5" drives to be used in desktop computers without the need for wiring adapters (a mounting adaptor is still likely to be needed to securely mount the drive).
SATA power connectors and data connectors have been criticized for their fragility and poor robustness — the thin plastic tops of the connectors (see power connector picture at right) can easily break due to shearing force when the user pulls the plug at a non-orthogonal angle, as can the connectors on drives they connect to. In the case of a broken connector on a hard drive, this could result in a complete loss of access to all data stored on the drive.
| Pin # | Function |
|---|---|
| 1 | Ground |
| 2 | A+ |
| 3 | A− |
| 4 | Ground |
| 5 | B− |
| 6 | B+ |
| 7 | Ground |
| - | coding notch |
| 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 be up to 1 m (39 in) long, 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-conductor wires, and are limited to 45 cm (18 in) in length by the PATA specification (however, cables up to 90 cm (36 in) are readily available). A ribbon cable (also known as multi-wire planar cable is a cable with many conducting wires running parallel to each other on the same flat plane Thus, SATA connectors and cables are easier to fit in closed spaces and reduce obstructions to air cooling. Air cooling is a method of dissipating Heat. It works by making the object to be cooled have a larger surface area or have an increased flow of air over its surface or both 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.
Parallel ATA uses single-ended signalling. Single-ended signalling is the simplest commonly used method of transmitting Electrical signals over Wires One wire carries a varying Voltage that represents In this system, the noise combines with the data signal during the signal transmission. Noise causes significant interference with the data signal at higher speeds. In order to reduce the noise interference, the driving voltage of Parallel ATA is as high as 5 V. Although the higher voltage can reduce the noise interference, the 5 V is too high for modern high speed silicon devices. Thus the fabrication cost of driving ICs is higher, and the speed is limited in comparison to low voltage silicon ICs.
In comparison, SATA systems use differential signaling. Differential signaling is a method of transmitting Information electrically by means of two complementary Signals sent on two separate wires In this system, it is easy to filter out the noise from the data signal at the receiving end. The higher noise rejection allows the SATA system to use only 500 mV peak-to-peak differential voltage to carry the signal at higher speeds without distortion or noise interference.
Compared with the 5 V driving voltage in PATA ribbon cables, the 0. 5 V in SATA cables in theory make the SATA system much more power efficient. However most SATA chipsets need significantly more power than PATA chipsets, due to the faster required encoding per wire.
| Pin # | Function | |
|---|---|---|
| 1–3 | 3. 3V | |
| 4–6 | Ground | |
| 7–9 | 5V | |
| 10 | Ground | |
| 11 | Staggered spinup (in supporting drives) |
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| 12 | Ground | |
| 13–15 | 12V | |
| A 15-pin Serial ATA power connector. Spin-up refers to the period of time taken by a traditional (non- solid state) Hard disk drive to accelerate its platters from a stopped state to an operational | ||
The SATA standard also specifies a new power connector. A power connector is an electrical Connector designed to carry a significant amount of electrical power, usually as DC or low-frequency AC. Like the data cable, it is wafer-based, but its wider 15-pin shape prevents accidental misidentification and forced insertion of the wrong connector type. Native SATA devices favor the SATA power-connector over the old four-pin Molex connector (found on all PATA equipment), although some SATA drives retain older 4-pin Molex. Molex connector is the vernacular term for a two-piece " pin and socket " interconnection most frequently disk drive connectors
There are more pins than the traditional connector for several reasons:
Adaptors are available to convert a 4-pin Molex connector to a SATA power connector. Molex connector is the vernacular term for a two-piece " pin and socket " interconnection most frequently disk drive connectors 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. Understanding this, drive manufacturers have largely left the 3. 3 V power lines unused. However, without 3. 3 V power, the SATA device may not be able to implement hotplugging as mentioned in the previous paragraph. Hot swapping and hot plugging are terms used to separately describe the functions of replacing system components hot swapping describes changing components like fans and
SATA is a point to point architecture. The connection between the controller and the storage device is direct.
In a modern PC system, the SATA controller is usually found on the motherboard, or installed in a PCI slot. Some SATA controllers have multiple SATA ports and can be connected to multiple storage devices. There are also port expanders which allow multiple storage devices to be connected to a single SATA controller port.
These high-speed transmission protocols use a logic encoding known as 8b10b. In Telecommunications 8b/10b is a Line code that maps 8-bit symbols to 10-bit symbols to achieve DC-balance (see The signal is sent using Non-return to Zero (NRZ) encoding with Low Voltage Differential Signaling (LVDS). In Telecommunication, a non-return-to-zero ( NRZ) Line code is a binary code in which "1s" are represented by one Significant Low-voltage differential signaling, or LVDS, is an electrical signaling system that can run at very high speeds over inexpensive Twisted-pair copper cables
In the 8b10b encoding the synchronizing signal is included in the data sequence. In Telecommunications 8b/10b is a Line code that maps 8-bit symbols to 10-bit symbols to achieve DC-balance (see This technique is known as Clock Data Recovery, because it doesn't use a separate synchronizing signal. Some digital data streams especially high-speed serial data streams (such as the raw stream of data from the magnetic head of a Disk drive) are sent without an accompanying clock Instead, it uses the serial signal's 0 to 1 transitions to recover the clock signal.
Standardized in mid-2004, eSATA defined separate cables, connectors, and revised electrical requirements for external applications:
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 almost 120 MB/s during real use,[2] more than twice the maximum transfer rate of USB 2. 0 or FireWire 400 (IEEE 1394a) and well in excess of the maximum transfer rate of FireWire 800, though the S3200 FireWire 1394b spec reaches ~400 MB/s (3. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently 2Gb/s). Finally, some low-level drive features, such as S.M.A.R.T., may not be available through USB or FireWire bridging. [6] eSATA does not suffer from these issues.
It is likely that eSATA co-exists with 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" (70 mm) 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.
Desktops computers that lack a built-in eSATA interface can be upgraded with the installation of an eSATA host bus adapter (HBA), while notebooks can be upgraded with Cardbus[7] or ExpressCard[8] versions of an eSATA HBA. In Computer hardware, a host controller, host adapter, or host bus adapter ( HBA) connects a host system (the Computer) to other In Computing, PC Card (originally '''PCMCIA''', or PCMCIA Card is the Form factor of a peripheral interface designed for Laptop computers ExpressCard is a Hardware standard replacing PC cards (also known as PCMCIA cards both developed by the Personal Computer Memory Card International Association With passive adapters the maximum cable length is reduced to 1 meter 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.
From the second half of 2008, SATA-IO expects eSATA to provide power to eSATA devices without the need for a separate power connection. In a news release from 2008-01-14, SATA-IO calls it the "Power Over eSATA initiative. "[9]
eSATA may be of interest to the enterprise and server market, which has already standardized on the Serial Attached SCSI (SAS) interface, because of its hotplug capability and low price. Introduction A typical Serial Attached SCSI system consists of the following basic components An Initiator is a device that originates device service
Prior to the final eSATA specification, there were a number of products designed for external connections of SATA drives. Some of these use the internal SATA connector or even connectors designed for other interface specifications, such as FireWire. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently These products are not eSATA compliant. The final eSATA specification features a specific connector designed for rough handling, similar to the regular SATA connector, but with reinforcements in both the male and female sides, inspired by the USB connector. It's harder to unplug, and can withstand yanking or wiggling which would break a male SATA connector (the hard drive or host adapter, usually fitted inside the computer). With an eSATA connector considerably more force is needed to damage the connector, and if it does break it is likely to be the female side, on the cable itself, which is relatively easy to replace.
At the device level, SATA and PATA devices are completely incompatible—they cannot be interconnected. At the application level, SATA devices are specified to look and act like PATA devices. [10] In early motherboard implementations of SATA, backward compatibility allowed SATA drives to be used as drop-in replacements for PATA drives, even without native (driver-level) support at the operating system level. In Technology, especially Computing (irrespective of platform a product is said to be backward compatible when it is able to take the place of an older product
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.
Powered enclosures are available for both PATA and SATA drives, which 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. The Peripheral Component Interconnect, or PCI Standard (commonly PCI) specifies a Computer bus for attaching peripheral devices to a Computer
SATA is designed to be backward and forward compatible with future revisions of the SATA standard. Forward compatibility (sometimes confused with Extensibility) is the ability of a system to gracefully accept Input intended for later versions of itself [11]
According to the hard drive manufacturer Maxtor, motherboard host controllers using the VIA and SIS chipsets VT8237, VT8237R, VT6420, VT6421L, SIS760, SIS964 found on the ECS 755-A2 which was manufactured in 2003, do not support SATA 3 Gbit/s drives. To address interoperability problems, the largest hard drive manufacturer Seagate/Maxtor have added a user-accessible jumper-switch known as the Force 150, to switch between 150 MB/s and 300 MB/s operation. [3] Users with a SATA 1. 5 Gbit/s motherboard with one of the listed chipsets should either buy an ordinary SATA 1. 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 card to add full SATA 3 Gbit/s capability and compatibility. Western Digital uses jumper setting called "OPT1 Enabled" to force 150 MB/s data transfer speed.
SCSI currently offers transfer rates higher than SATA, but is a more complex bus usually resulting in higher manufacturing cost. Some drive manufacturers offer longer warranties for SCSI devices, however, indicating a possibly higher manufacturing quality control of SCSI devices compared to PATA/SATA devices. 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. 0 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. SATA devices are generally compatible with SAS enclosures and adapters, while SCSI devices cannot be directly connected to a SATA bus. Introduction A typical Serial Attached SCSI system consists of the following basic components An Initiator is a device that originates device service
SCSI, SAS and FC drives are typically more expensive so they are traditionally used in servers and disk arrays where the added cost is justifiable. A disk array is a Disk storage system which contains multiple Disk drives It is differentiated from a Disk enclosure, in that an array has Cache Inexpensive ATA and SATA drives evolved in the home computer market, hence the general opinion is that they are less reliable. A home computer was a class of Personal computer entering the market in 1977 and becoming common during the 1980s As those two worlds started to overlap, the subject of reliability became somewhat controversial. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device It is worth noting that generally a disk drive has a low failure rate because of increased quality of its heads, platters and supporting manufacturing processes, not because of having a certain interface.
| Name | Raw bandwidth (Mbit/s) | Transfer speed (MB/s) | Max. A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) A megabyte is a unit of Information or Computer storage equal to either 106 (1000000 Bytes or 220 (1048576 bytes depending on cable length (m) | Power provided | Devices per Channel |
|---|---|---|---|---|---|
| SAS | 3000 | 375 | 8 | No | 4 |
| eSATA | 3000 | 300 | 2 with eSATA HBA (1 with passive adapter) | No [12] | 1 (15 with port multiplier) |
| SATA 300 | 3000 | 300 | 1 | No | 1 (15 with port multiplier) |
| SATA 150 | 1500 | 150 | 1 | No | 1 per line |
| PATA 133 | 1064 | 133 | 0. Introduction A typical Serial Attached SCSI system consists of the following basic components An Initiator is a device that originates device service A Serial ATA port multiplier is a device that allows one to connect multiple SATA devices to a single SATA host port in a similar manner to that of a USB hub. A Serial ATA port multiplier is a device that allows one to connect multiple SATA devices to a single SATA host port in a similar manner to that of a USB hub. AT Attachment with Packet Interface ( ATA/ATAPI) is a standard interface used to connect storage devices such as Hard disks Solid-state 46 (18 inches) | No | 2 |
| FireWire 3200 | 3144 | 393 | 100; alternate cables available for 100 m+ | 15 W, 12–25 V | 63 (with hub) |
| FireWire 800 | 786 | 98. Inches redirects here To see the Les Savy Fav album see Inches. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently 25 | 100[13] | 15 W, 12–25 V | 63 (with hub) |
| FireWire 400 | 393 | 49. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently 13 | 4. 5[13][14] | 15 W, 12–25 V | 63 (with hub) |
| USB 2. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. 0 | 480 | 60 | 5[15] | 2. 5 W, 5 V | 127 (with hub) |
| Ultra-320 SCSI | 2560 | 320 | 12 | No | 16 |
| Fibre Channel over copper cable |
4000 | 400 | 12 | No | 126 (16777216 with switches) |
| Fibre Channel over fiber |
10520 | 2000 | 2–50000 | No | 126 (16777216 with switches) |
| Infiniband 12X Quad-rate |
120000 | 12000 | 5 (copper)[16][17]
<10000 (fiber) |
No | 1 with Point to point Many with switched fabric |
Unlike PATA, both SATA and eSATA are designed to support hot-swapping. The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. Fibre Channel, or FC, is a Gigabit -speed network technology primarily used for Storage networking. In the Computer storage field a Fibre Channel switch is a Network switch compatible with the Fibre Channel (FC protocol Fibre Channel, or FC, is a Gigabit -speed network technology primarily used for Storage networking. In the Computer storage field a Fibre Channel switch is a Network switch compatible with the Fibre Channel (FC protocol InfiniBand is a Switched fabric communications link primarily used in High-performance computing. Switched fabric, switching fabric, or just fabric, is a Network topology where network nodes connect with each other via one or more Network switches 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), but requisite support is less common on SATA host adapters. Hot swapping and hot plugging are terms used to separately describe the functions of replacing system components hot swapping describes changing components like fans and In Computer hardware, a host controller, host adapter, or host bus adapter ( HBA) connects a host system (the Computer) to other
USB allows hot-swapping; this is supported by virtually every current operating system. However, USB-based storage hardware can infrequently sustain data loss when disconnected. This problem exists with media players and digital cameras using flash memory as well as mobile 2. 5-inch (64 mm) USB hard drives. Firmware damage and data loss can occasionally result from unclean spin-downs and power loss when the drive or device is removed from the USB port without first initiating a device shutdown via the computer's operating system. [18]
SCSI devices with SCA-2 connectors are designed for hot-swapping. Many server and RAID systems provide hardware support for transparent hot-swapping. The SCSI standard prior to SCA-2 connectors was not designed for hot-swapping, but, in practice, most RAID implementations support hot-swapping of hard disks.
Serial Attached SCSI (SAS) is designed for swapping. Introduction A typical Serial Attached SCSI system consists of the following basic components An Initiator is a device that originates device service