Light Peak
Encyclopedia
Thunderbolt is an interface for connecting peripheral devices to a computer via an expansion bus
. Thunderbolt was developed by Intel and brought to market with technical collaboration from Apple Inc. It was introduced commercially on Apple's updated MacBook Pro
lineup on February 24, 2011, using the same port and connector as Mini DisplayPort
. Though initially registered with Apple Inc., full rights of the Thunderbolt technology trademark belong to Intel Corp., and subsequently led to the transfer of the registration.
Thunderbolt combines PCI Express
and DisplayPort
into a serial data
interface that can be carried over longer and less costly cables. Because PCI Express is widely supported by device vendors and built into most of Intel's modern chipset
s, Thunderbolt can be added to existing products with relative ease. Thunderbolt driver chips fold the data from these two sources together, and split them back apart again for consumption within the devices. This makes the system backward compatible with existing DisplayPort hardware upstream of the driver.
The interface was originally intended to run on an optical physical layer using components and flexible optical fiber
cabling developed by Intel partners and at Intel's Silicon Photonics lab. The Intel technology at the time was marketed under the name Light Peak, today (2011) referred to as Silicon Photonics Link. However, it turned out that conventional copper
wiring could furnish the desired 10 Gbit/s Thunderbolt bandwidth per channel at lower cost. Later versions of Thunderbolt are still planned to introduce an optical physical layer based on Intel silicon photonics technology.
The Intel and Apple implementation of the port adapter integrates PCI Express
data and DisplayPort
data, allowing them to be carried over the same cable simultaneously. A single Thunderbolt port supports hubs as well as a daisy chain of up to seven Thunderbolt devices; up to two of these devices may be high-resolution displays using DisplayPort.
Apple sells existing DisplayPort adapters for DVI
, dual-link DVI, HDMI
, and VGA
output from the Thunderbolt port, showing broad compatibility.
introduced Light Peak at the 2009 Intel Developer Forum
(IDF), using a prototype Mac Pro
motherboard to run two 1080p
video streams plus LAN
and storage devices over a single 30-meter optical cable with modified USB
ends.
The system was driven by a prototype PCI Express
card, with two optical buses powering four ports.
At the show, Intel claimed that Light Peak-equipped systems would begin to appear in 2010. A Youtube video simultaneously published by Intel also showed Light Peak interfacing with HD cameras, laptops, docking stations, and HD monitors. Jason Ziller, Head of the Intel Optical I/O Program Office also demonstrated the internal components of the technology under a microscope and the outputing of data through an oscilloscope.
On 4 May 2010, in Brussels, Intel demonstrated a laptop with a Light Peak connector, indicating that the technology had shrunk small enough to fit inside such a device, and had the laptop send two simultaneous HD video streams down the connection, indicating that at least some fraction of the software/firmware stacks and protocols were functional. At the same demonstration, Intel officials said they expected hardware manufacturing to begin around the end of 2010.
In September 2010, some early commercial prototypes from manufacturers were demonstrated at Intel Developer Forum
2010.
technology, Thunderbolt switched to electrical connections to reduce costs and to supply up to 10W of power to connected devices.
In 2009, Intel officials said the company was "working on bundling the optical fibre with copper wire so Light Peak can be used to power devices plugged into the PC."
In 2010, Intel said the original intent was "to have one single connector technology" that would allow "electrical USB 3.0 […] and piggyback on USB 3.0 or 4.0 DC power."
In January 2011, Intel's David Perlmutter told Computerworld
that initial Thunderbolt implementations would be based on copper wires.
"The copper came out very good, surprisingly better than what we thought," he said.
Intel and industry partners are still developing optical Thunderbolt hardware and cables.
The optical fiber cable
s are to run "tens of meters" but will not supply power, at least not initially.
They are to have two 62.5-micron-wide fibers to transport an infrared signal up to 100 metres (328.1 ft).
The conversion of electrical signal to optical will be embedded into the cable itself, allowing the current DisplayPort socket to be future compatible, but eventually Intel hopes for a purely optical transceiver assembly embedded in the PC.
update would include some sort of new data port, and most of the speculation suggested it would be Light Peak.
At the time, there were no details on the physical implementation, and mock-ups appeared showing a system similar to the earlier Intel demos using a combined USB/Light Peak port.
Shortly before the release of the new machines, the USB Implementers Forum
(USB-IF) announced they would not allow this, stating that USB was not open to modification in this way.
In spite of these comments and speculation, the introduction came as a major surprise when it was revealed that the port was based on DisplayPort, not USB. As the system was described, Intel's solution to the display connection problem became clear: Thunderbolt controllers fold data from existing DisplayPort systems with data from the PCI Express port into a single cable. Older displays, using DisplayPort 1.1 or earlier, have to be located at the end of a Thunderbolt device chain, but newer displays can be placed anywhere along the line. Thunderbolt devices can go anywhere on the chain. In this respect, Thunderbolt shares a relationship with the older ACCESS.bus
system, which used the display connector to support a low-speed bus.
Apple published technical details explaining that 6 daisy-chained peripherals are supported per Thunderbolt port, and that the Display should lie at the end of the chain.
Apple
Sony
In February 2011, Apple introduced its new line of MacBook Pro laptop computers and announced the technology's commercial name would be Thunderbolt, with these machines being the first to feature the new I/O technology.
In May 2011, Apple announced a new line of iMac
s that include the Thunderbolt interface.
The Thunderbolt port on the new Macs is in the same location relative to other ports and maintains the same physical dimensions and pin out as the legacy Mini DisplayPort connector. The primary visual differentiation on Thunderbolt equipped Macs is a Thunderbolt symbol instead of a DisplayPort symbol next to the port opening.
Apple's legacy DisplayPort
standard is partially compatible with Thunderbolt, as the two share a physically compatible Mini DisplayPort
connector. The Target Display mode on iMac
s requires a Thunderbolt cable to accept a video-in signal from another Thunderbolt-capable computer. Mini DisplayPort monitors function correctly as an external monitor without an adaptor if they are either the only or the last device in the Thunderbolt device chain.
Intel announced that a developer kit
would be released in the second quarter of 2011,
while manufacturers of hardware development equipment have indicated they will add support for the testing and development of Thunderbolt devices. The developer kit was not yet available , with Intel saying that interested parties needed to keep checking later.
Because the PCIe bus does not carry video data, it is unclear whether a standalone PCIe card could offer a Thunderbolt port. The Intel Thunderbolt Technology Brief does not give a conclusive answer.
Intel disclosed documentation where video stream is sent to a dual-thunderbolt controller, with the video stream being only sent to one of the Thunderbolt Port, giving the assumption that video stream is not mandatory on Thunderbolt implementation.
Thunderbolt can be implemented on PCIe graphics cards, which have access to DisplayPort data and PCI express connectivity, or on the motherboard of new devices, such as the MacBook Pro.
Thunderbolt controllers on the host and peripherals multiplex
the PCIe and DisplayPort data into packets at the transport layer and demultiplex them at the destination.
Thunderbolt is interoperable with [DisplayPort] 1.2 compatible devices. When connected to a DisplayPort compatible device the Thunderbolt port can provide a native DisplayPort signal with 4 lanes of output data at no more than 5.4 Gbit/s per lane. When connected to a Thunderbolt device the per-lane data rate becomes 10 Gbit/s and the 4 lanes are configured as 2 channels with each bidirectional 10 Gbit/s channel comprising one lane of input and one lane of output.
This issue exists with many high-speed expansion buses, including PC Card
, ExpressCard
and the IEEE 1394 interface
, commonly known as FireWire.
It is worth noting that a number of Intel processors since the introduction of the Nehalem microarchitecture (that is, a number of CPU branded Core i5, Core i7, or later) support VT-d, an IOMMU
implementation. This allows the operating system
(OS) to isolate a device in its own virtual memory
address space (in a manner analogous to the isolation of processes from one another using the MMU
). Devices are thus prevented from having access to all of physical memory.
, it includes circuitry inside the connectors.
The cable has 5 wires, 1 for management and two uni-directional pairs, one for incoming and second for outgoing traffic.
Expansion bus
An expansion bus is made up of electronic pathways which move information between the internal hardware of a computer system and peripheral devices. It is a collection of wires and protocols that allows for the expansion of a computer.- History :The first kit-built microcomputers used a bus design...
. Thunderbolt was developed by Intel and brought to market with technical collaboration from Apple Inc. It was introduced commercially on Apple's updated MacBook Pro
MacBook Pro
The MacBook Pro is a line of Macintosh portable computers introduced in January 2006 by Apple. It replaced the PowerBook G4 and was the second model, after the iMac, to be announced in the Apple–Intel transition...
lineup on February 24, 2011, using the same port and connector as Mini DisplayPort
Mini DisplayPort
The Mini DisplayPort is a miniaturized version of the DisplayPort digital audio-visual interface. Apple, Inc. announced the development in the fourth quarter of 2008, and now applies it in the LED Cinema Display and in all new Macintosh computers: MacBook, MacBook Pro, MacBook Air, iMac, Mac mini,...
. Though initially registered with Apple Inc., full rights of the Thunderbolt technology trademark belong to Intel Corp., and subsequently led to the transfer of the registration.
Thunderbolt combines PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
and DisplayPort
DisplayPort
DisplayPort is a digital display interface standard produced by the Video Electronics Standards Association . The specification defines a royalty-free digital interconnect for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor...
into a serial data
Serial communication
In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
interface that can be carried over longer and less costly cables. Because PCI Express is widely supported by device vendors and built into most of Intel's modern chipset
Chipset
A chipset, PC chipset, or chip set refers to a group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.- Computers :...
s, Thunderbolt can be added to existing products with relative ease. Thunderbolt driver chips fold the data from these two sources together, and split them back apart again for consumption within the devices. This makes the system backward compatible with existing DisplayPort hardware upstream of the driver.
The interface was originally intended to run on an optical physical layer using components and flexible optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
cabling developed by Intel partners and at Intel's Silicon Photonics lab. The Intel technology at the time was marketed under the name Light Peak, today (2011) referred to as Silicon Photonics Link. However, it turned out that conventional copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
wiring could furnish the desired 10 Gbit/s Thunderbolt bandwidth per channel at lower cost. Later versions of Thunderbolt are still planned to introduce an optical physical layer based on Intel silicon photonics technology.
The Intel and Apple implementation of the port adapter integrates PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
data and DisplayPort
DisplayPort
DisplayPort is a digital display interface standard produced by the Video Electronics Standards Association . The specification defines a royalty-free digital interconnect for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor...
data, allowing them to be carried over the same cable simultaneously. A single Thunderbolt port supports hubs as well as a daisy chain of up to seven Thunderbolt devices; up to two of these devices may be high-resolution displays using DisplayPort.
Apple sells existing DisplayPort adapters for DVI
Digital Visual Interface
The Digital Visual Interface is a video interface standard covering the transmission of video between a source device and a display device. The DVI standard has achieved widespread acceptance in the PC industry, both in desktop PCs and monitors...
, dual-link DVI, HDMI
HDMI
HDMI is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA...
, and VGA
Video Graphics Array
Video Graphics Array refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987, but through its widespread adoption has also come to mean either an analog computer display standard, the 15-pin D-subminiature VGA connector or the 640×480 resolution...
output from the Thunderbolt port, showing broad compatibility.
Introduction
IntelIntel Corporation
Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...
introduced Light Peak at the 2009 Intel Developer Forum
Intel Developer Forum
Intel Developer Forum , is a gathering of technologists to discuss Intel products and products based around Intel products. The first IDF was in 1997...
(IDF), using a prototype Mac Pro
Mac Pro
The Mac Pro is a workstation computer manufactured by Apple Inc. The machines are based on Xeon microprocessors, but are similar to the Power Mac G5 they replaced in terms of outward appearance and expansion capabilities...
motherboard to run two 1080p
1080p
1080p is the shorthand identification for a set of HDTV high-definition video modes that are characterized by 1080 horizontal lines of resolution and progressive scan, meaning the image is not interlaced as is the case with the 1080i display standard....
video streams plus LAN
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
and storage devices over a single 30-meter optical cable with modified USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
ends.
The system was driven by a prototype PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
card, with two optical buses powering four ports.
At the show, Intel claimed that Light Peak-equipped systems would begin to appear in 2010. A Youtube video simultaneously published by Intel also showed Light Peak interfacing with HD cameras, laptops, docking stations, and HD monitors. Jason Ziller, Head of the Intel Optical I/O Program Office also demonstrated the internal components of the technology under a microscope and the outputing of data through an oscilloscope.
On 4 May 2010, in Brussels, Intel demonstrated a laptop with a Light Peak connector, indicating that the technology had shrunk small enough to fit inside such a device, and had the laptop send two simultaneous HD video streams down the connection, indicating that at least some fraction of the software/firmware stacks and protocols were functional. At the same demonstration, Intel officials said they expected hardware manufacturing to begin around the end of 2010.
In September 2010, some early commercial prototypes from manufacturers were demonstrated at Intel Developer Forum
Intel Developer Forum
Intel Developer Forum , is a gathering of technologists to discuss Intel products and products based around Intel products. The first IDF was in 1997...
2010.
Copper vs. optical
Originally conceived as an opticalOptics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
technology, Thunderbolt switched to electrical connections to reduce costs and to supply up to 10W of power to connected devices.
In 2009, Intel officials said the company was "working on bundling the optical fibre with copper wire so Light Peak can be used to power devices plugged into the PC."
In 2010, Intel said the original intent was "to have one single connector technology" that would allow "electrical USB 3.0 […] and piggyback on USB 3.0 or 4.0 DC power."
In January 2011, Intel's David Perlmutter told Computerworld
Computerworld
Computerworld is an IT magazine that provides information for senior IT leaders. It is published in many countries around the world under the same or similar names. Its publisher is International Data Group. Computerworld serves the needs of IT management via print and online...
that initial Thunderbolt implementations would be based on copper wires.
"The copper came out very good, surprisingly better than what we thought," he said.
Intel and industry partners are still developing optical Thunderbolt hardware and cables.
The optical fiber cable
Optical fiber cable
An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed....
s are to run "tens of meters" but will not supply power, at least not initially.
They are to have two 62.5-micron-wide fibers to transport an infrared signal up to 100 metres (328.1 ft).
The conversion of electrical signal to optical will be embedded into the cable itself, allowing the current DisplayPort socket to be future compatible, but eventually Intel hopes for a purely optical transceiver assembly embedded in the PC.
Market introduction
It was long rumoured that the early-2011 MacBook ProMacBook Pro
The MacBook Pro is a line of Macintosh portable computers introduced in January 2006 by Apple. It replaced the PowerBook G4 and was the second model, after the iMac, to be announced in the Apple–Intel transition...
update would include some sort of new data port, and most of the speculation suggested it would be Light Peak.
At the time, there were no details on the physical implementation, and mock-ups appeared showing a system similar to the earlier Intel demos using a combined USB/Light Peak port.
Shortly before the release of the new machines, the USB Implementers Forum
USB Implementers Forum
The USB Implementers Forum is a non-profit organisation to promote and support the Universal Serial Bus. Its main activities are the promotion and marketing of USB, Wireless USB, USB On-The-Go, and the maintenance of the specifications, as well as a compliance program.It was formed in 1995 by the...
(USB-IF) announced they would not allow this, stating that USB was not open to modification in this way.
In spite of these comments and speculation, the introduction came as a major surprise when it was revealed that the port was based on DisplayPort, not USB. As the system was described, Intel's solution to the display connection problem became clear: Thunderbolt controllers fold data from existing DisplayPort systems with data from the PCI Express port into a single cable. Older displays, using DisplayPort 1.1 or earlier, have to be located at the end of a Thunderbolt device chain, but newer displays can be placed anywhere along the line. Thunderbolt devices can go anywhere on the chain. In this respect, Thunderbolt shares a relationship with the older ACCESS.bus
ACCESS.bus
ACCESS.bus is a peripheral-interconnect computer bus developed by Philips in the early 1990s. It is similar in purpose to USB, in that it allows low-speed devices to be added or removed from a computer on the fly...
system, which used the display connector to support a low-speed bus.
Apple published technical details explaining that 6 daisy-chained peripherals are supported per Thunderbolt port, and that the Display should lie at the end of the chain.
Apple
- MacBook ProMacBook ProThe MacBook Pro is a line of Macintosh portable computers introduced in January 2006 by Apple. It replaced the PowerBook G4 and was the second model, after the iMac, to be announced in the Apple–Intel transition...
(February 24, 2011) - iMacIMacThe iMac is a range of all-in-one Macintosh desktop computers built by Apple. It has been the primary part of Apple's consumer desktop offerings since its introduction in 1998, and has evolved through five distinct forms....
(May 3, 2011) - MacBook AirMacBook AirThe MacBook Air family is a line of Apple ultraportable Macintosh notebook computers.The first-generation MacBook Air was a 13.3"-only model, previously promoted as the World's Thinnest Notebook, introduced at the Macworld Conference & Expo on January 15, 2008. It featured a custom Intel Merom CPU...
(July 20, 2011) - Mac MiniMac MiniThe Mac Mini is a small form factor desktop computer manufactured by Apple Inc. Like earlier mini-ITX PC designs, it is uncommonly small for a desktop computer: 7.7 inches square and 1.4 inches tall. It weighs 2.7 pounds...
(July 20, 2011) - Mac ProMac ProThe Mac Pro is a workstation computer manufactured by Apple Inc. The machines are based on Xeon microprocessors, but are similar to the Power Mac G5 they replaced in terms of outward appearance and expansion capabilities...
(N/A)
Sony
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
- Vaio Z21Sony VAIO Z seriesSony has used the Z model moniker for its high-end ultraportable notebook computers since 2000. Unlike other Sony models, the Z has always been manufactured in Japan....
(N/A)
In February 2011, Apple introduced its new line of MacBook Pro laptop computers and announced the technology's commercial name would be Thunderbolt, with these machines being the first to feature the new I/O technology.
In May 2011, Apple announced a new line of iMac
IMac
The iMac is a range of all-in-one Macintosh desktop computers built by Apple. It has been the primary part of Apple's consumer desktop offerings since its introduction in 1998, and has evolved through five distinct forms....
s that include the Thunderbolt interface.
The Thunderbolt port on the new Macs is in the same location relative to other ports and maintains the same physical dimensions and pin out as the legacy Mini DisplayPort connector. The primary visual differentiation on Thunderbolt equipped Macs is a Thunderbolt symbol instead of a DisplayPort symbol next to the port opening.
Apple's legacy DisplayPort
DisplayPort
DisplayPort is a digital display interface standard produced by the Video Electronics Standards Association . The specification defines a royalty-free digital interconnect for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor...
standard is partially compatible with Thunderbolt, as the two share a physically compatible Mini DisplayPort
Mini DisplayPort
The Mini DisplayPort is a miniaturized version of the DisplayPort digital audio-visual interface. Apple, Inc. announced the development in the fourth quarter of 2008, and now applies it in the LED Cinema Display and in all new Macintosh computers: MacBook, MacBook Pro, MacBook Air, iMac, Mac mini,...
connector. The Target Display mode on iMac
IMac
The iMac is a range of all-in-one Macintosh desktop computers built by Apple. It has been the primary part of Apple's consumer desktop offerings since its introduction in 1998, and has evolved through five distinct forms....
s requires a Thunderbolt cable to accept a video-in signal from another Thunderbolt-capable computer. Mini DisplayPort monitors function correctly as an external monitor without an adaptor if they are either the only or the last device in the Thunderbolt device chain.
Intel announced that a developer kit
Software development kit
A software development kit is typically a set of software development tools that allows for the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar platform.It may be something as simple...
would be released in the second quarter of 2011,
while manufacturers of hardware development equipment have indicated they will add support for the testing and development of Thunderbolt devices. The developer kit was not yet available , with Intel saying that interested parties needed to keep checking later.
Description
Thunderbolt is based on the Mini DisplayPort connector developed by Apple. This is electrically identical to "normal" DisplayPort connectors, but uses a smaller connector that is more suitable for use on laptops and other consumer devices. It is expected that Thunderbolt's use of this connector will drive wider acceptance.Because the PCIe bus does not carry video data, it is unclear whether a standalone PCIe card could offer a Thunderbolt port. The Intel Thunderbolt Technology Brief does not give a conclusive answer.
Intel disclosed documentation where video stream is sent to a dual-thunderbolt controller, with the video stream being only sent to one of the Thunderbolt Port, giving the assumption that video stream is not mandatory on Thunderbolt implementation.
Thunderbolt can be implemented on PCIe graphics cards, which have access to DisplayPort data and PCI express connectivity, or on the motherboard of new devices, such as the MacBook Pro.
Thunderbolt controllers on the host and peripherals multiplex
Multiplexing
The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
the PCIe and DisplayPort data into packets at the transport layer and demultiplex them at the destination.
Thunderbolt is interoperable with [DisplayPort] 1.2 compatible devices. When connected to a DisplayPort compatible device the Thunderbolt port can provide a native DisplayPort signal with 4 lanes of output data at no more than 5.4 Gbit/s per lane. When connected to a Thunderbolt device the per-lane data rate becomes 10 Gbit/s and the 4 lanes are configured as 2 channels with each bidirectional 10 Gbit/s channel comprising one lane of input and one lane of output.
Security
Since Thunderbolt extends the PCI Express bus, which is the main expansion bus in current systems, it allows very low-level access to the system. PCI devices need to have unlimited access to memory, and may thus compromise security.This issue exists with many high-speed expansion buses, including PC Card
PC Card
In computing, PC Card is the form factor of a peripheral interface designed for laptop computers. The PC Card standard was defined and developed by the Personal Computer Memory Card International Association which itself was created by a number of computer industry companies in the United States...
, ExpressCard
ExpressCard
ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
and the IEEE 1394 interface
IEEE 1394 interface
The IEEE 1394 interface is a serial bus interface standard for high-speed communications and isochronous real-time data transfer, frequently used by personal computers, as well as in digital audio, digital video, automotive, and aeronautics applications. The interface is also known by the brand...
, commonly known as FireWire.
It is worth noting that a number of Intel processors since the introduction of the Nehalem microarchitecture (that is, a number of CPU branded Core i5, Core i7, or later) support VT-d, an IOMMU
IOMMU
In computing, an input/output memory management unit is a memory management unit that connects a DMA-capable I/O bus to the main memory...
implementation. This allows the operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
(OS) to isolate a device in its own virtual memory
Virtual memory
In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
address space (in a manner analogous to the isolation of processes from one another using the MMU
Memory management unit
A memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...
). Devices are thus prevented from having access to all of physical memory.
Cost
As of July 2011, the first two meter Thunderbolt cable from Apple costs US$49.00. As an active cableActive Cables
Active cables are copper cables for data transmission that use a silicon chip to boost the performance of the cable. Without a chip, a cable is considered a 'passive' cable. Passive cables are liable to degrade the data they carry, due to such "channel impairments" as attenuation, crosstalk and...
, it includes circuitry inside the connectors.
The cable has 5 wires, 1 for management and two uni-directional pairs, one for incoming and second for outgoing traffic.
See also
- Computer bus
- Apple Thunderbolt DisplayApple Thunderbolt DisplayThe Apple Thunderbolt Display is the current flat panel computer monitor sold by Apple Inc. Introduced on July 20, 2011, it immediately replaced the LED Cinema Display, continuing with the same form factor and technical specification for the display portion of the product...
- Optical interconnectOptical interconnectOptical interconnect is a way of communication by optical cables. Compared to traditional cables, optical wires are capable of a much higher bandwidth, from 10 Gb/s up to 100 Gb/s....
- Parallel optical interfaceParallel optical interfaceA parallel optical interface is a form of fiber optic technology aimed primarily at communications and networking over relatively short distances , and at high bandwidths....
- Optical communicationOptical communicationOptical communication is any form of telecommunication that uses light as the transmission medium.An optical communication system consists of a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the...
- Interconnect bottleneckInterconnect bottleneckThe interconnect bottleneck, the point at which integrated circuits reach their capacity, is expected sometime around 2010.Improved performance of computer systems has been achieved, in large part, by downscaling the IC minimum feature size. This allows the basic IC building block, the transistor,...
- Optical fiber cableOptical fiber cableAn optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed....
- IEEE 1394 interfaceIEEE 1394 interfaceThe IEEE 1394 interface is a serial bus interface standard for high-speed communications and isochronous real-time data transfer, frequently used by personal computers, as well as in digital audio, digital video, automotive, and aeronautics applications. The interface is also known by the brand...
(FireWire) - USBUniversal Serial BusUSB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
- DisplayPortDisplayPortDisplayPort is a digital display interface standard produced by the Video Electronics Standards Association . The specification defines a royalty-free digital interconnect for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor...
/ Mini DisplayPortMini DisplayPortThe Mini DisplayPort is a miniaturized version of the DisplayPort digital audio-visual interface. Apple, Inc. announced the development in the fourth quarter of 2008, and now applies it in the LED Cinema Display and in all new Macintosh computers: MacBook, MacBook Pro, MacBook Air, iMac, Mac mini,... - ePCIe
- List of computer peripheral bus bit rates