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HyperTransport (HT), formerly known as Lightning Data Transport (LDT), is a bidirectional serial/parallel high-bandwidth, low-latency point-to-point link that was introduced on April 2 2001. The HyperTransport Consortium
HyperTransport Consortium

The HyperTransport Consortium is an industry consortium responsible for specifying and promoting the computer bus technology called HyperTransport....
 is in charge of promoting and developing HyperTransport technology. The technology is used by AMD and Transmeta
Transmeta

Transmeta Corporation was a United States-based corporation that licensed low power semiconductor intellectual property. Transmeta originally produced very long instruction word code morphing microprocessors, with a focus on reducing power consumption in electronic devices....
 in x86 processors, PMC-Sierra
PMC-Sierra

PMC-Sierra is a fabless semiconductor company which develops and sells devices into the communications, storage, printing, and embedded computing marketplaces....
, Broadcom
Broadcom

Broadcom Corporation is an United States supplier of integrated circuits for broadband communications. Founded in 1991 by Henry Samueli and Henry T....
, and Raza Microelectronics in MIPS
MIPS architecture

MIPS is a RISC instruction set architecture developed by MIPS Technologies . In the mid to late 1990s, it was estimated that one in three RISC microprocessors produced were MIPS implementations....
 microprocessors, AMD, NVIDIA
NVIDIA

Nvidia is a multinational corporation specializing in the manufacture of graphics processing unit technologies for workstations, desktop computers, and mobile devices....
, VIA
VIA Technologies

VIA Technologies is a Taiwanese manufacturer of integrated circuits, mainly motherboard chipsets, Central processing unit, and computer memory, and is part of the Formosa Plastics Group....
 and SiS
Silicon Integrated Systems

Silicon Integrated Systems is a company that manufactures, among other things, motherboard chipsets. The company was founded in 1987 in Hsinchu Science Park, Taiwan....
 in PC chipsets, HP
Hewlett-Packard

The Hewlett-Packard Company , commonly referred to as HP, is a technology corporation headquartered in Palo Alto, California, United States....
, Sun Microsystems
Sun Microsystems

Sun Microsystems, Inc. is a multinational corporation vendor of computers, computer components, computer software, and information technology services, founded on February 24, 1982....
, IBM
IBM

International Business Machines Corporation, abbreviated IBM and nicknamed "Big Blue" , is a multinational corporation computer technology and consulting corporation headquartered in Armonk, New York, New York, United States....
, and Flextronics
Flextronics

Flextronics International Ltd. is a contract electronics maker which provides electronics manufacturing facilities to original equipment manufacturers ....
 in servers, Cray
Cray

Cray Inc. is a supercomputer manufacturer based in Seattle, Washington. The company's predecessor, Cray Research, Inc. , was founded in 1972 by computer designer Seymour Cray....
, Newisys
Newisys

Newisys, a Server and Storage company with expertise in glue-chips for Opterons, based in Austin, Texas, was founded by Phillip Doyce Hester in 2000, and was acquired in 2004 by manufacturer Sanmina-SCI Corporation....
, QLogic
QLogic

File:ML-QLOGICNFCCONN.JPGQLogic Corporation is a Aliso Viejo, California-based manufacturer of storage and system networking infrastructure solutions....
, and XtremeData, Inc.






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Encyclopedia


HyperTransport (HT), formerly known as Lightning Data Transport (LDT), is a bidirectional serial/parallel high-bandwidth, low-latency point-to-point link that was introduced on April 2 2001. The HyperTransport Consortium
HyperTransport Consortium

The HyperTransport Consortium is an industry consortium responsible for specifying and promoting the computer bus technology called HyperTransport....
 is in charge of promoting and developing HyperTransport technology. The technology is used by AMD and Transmeta
Transmeta

Transmeta Corporation was a United States-based corporation that licensed low power semiconductor intellectual property. Transmeta originally produced very long instruction word code morphing microprocessors, with a focus on reducing power consumption in electronic devices....
 in x86 processors, PMC-Sierra
PMC-Sierra

PMC-Sierra is a fabless semiconductor company which develops and sells devices into the communications, storage, printing, and embedded computing marketplaces....
, Broadcom
Broadcom

Broadcom Corporation is an United States supplier of integrated circuits for broadband communications. Founded in 1991 by Henry Samueli and Henry T....
, and Raza Microelectronics in MIPS
MIPS architecture

MIPS is a RISC instruction set architecture developed by MIPS Technologies . In the mid to late 1990s, it was estimated that one in three RISC microprocessors produced were MIPS implementations....
 microprocessors, AMD, NVIDIA
NVIDIA

Nvidia is a multinational corporation specializing in the manufacture of graphics processing unit technologies for workstations, desktop computers, and mobile devices....
, VIA
VIA Technologies

VIA Technologies is a Taiwanese manufacturer of integrated circuits, mainly motherboard chipsets, Central processing unit, and computer memory, and is part of the Formosa Plastics Group....
 and SiS
Silicon Integrated Systems

Silicon Integrated Systems is a company that manufactures, among other things, motherboard chipsets. The company was founded in 1987 in Hsinchu Science Park, Taiwan....
 in PC chipsets, HP
Hewlett-Packard

The Hewlett-Packard Company , commonly referred to as HP, is a technology corporation headquartered in Palo Alto, California, United States....
, Sun Microsystems
Sun Microsystems

Sun Microsystems, Inc. is a multinational corporation vendor of computers, computer components, computer software, and information technology services, founded on February 24, 1982....
, IBM
IBM

International Business Machines Corporation, abbreviated IBM and nicknamed "Big Blue" , is a multinational corporation computer technology and consulting corporation headquartered in Armonk, New York, New York, United States....
, and Flextronics
Flextronics

Flextronics International Ltd. is a contract electronics maker which provides electronics manufacturing facilities to original equipment manufacturers ....
 in servers, Cray
Cray

Cray Inc. is a supercomputer manufacturer based in Seattle, Washington. The company's predecessor, Cray Research, Inc. , was founded in 1972 by computer designer Seymour Cray....
, Newisys
Newisys

Newisys, a Server and Storage company with expertise in glue-chips for Opterons, based in Austin, Texas, was founded by Phillip Doyce Hester in 2000, and was acquired in 2004 by manufacturer Sanmina-SCI Corporation....
, QLogic
QLogic

File:ML-QLOGICNFCCONN.JPGQLogic Corporation is a Aliso Viejo, California-based manufacturer of storage and system networking infrastructure solutions....
, and XtremeData, Inc. in high performance computing, and Cisco Systems
Cisco Systems

Cisco Systems, Inc. is a multinational corporation with more than 66,000 employees and annual revenue of United States dollar39 billion as of 2008....
 in routers.

Overview


Multi-Link High-Speed interconnect

HyperTransport comes in four speed versions — 1.x, 2.0, 3.0, and 3.1 — which run from 200 MHz
Hertz

The hertz is a measure of frequency per unit of time, or the number of list of cycles per second. It is the SI base unit of frequency in the International System of Units , and is used worldwide in both general-purpose and scientific contexts....
 to 3.2 GHz
Hertz

The hertz is a measure of frequency per unit of time, or the number of list of cycles per second. It is the SI base unit of frequency in the International System of Units , and is used worldwide in both general-purpose and scientific contexts....
. It is also a DDR or "Double Data Rate
Double data rate

In computing, a computer bus operating with double data rate transfers data on both the rising and falling edges of the clock signal. This is also known as double pumped, dual-pumped, and double transition....
" connection, meaning it sends data on both the rising and falling edges of the clock signal
Clock signal

In electronics and especially Synchronous logic digital circuits, a clock signal is a Signalling used to coordinate the actions of two or more Electronic circuit....
. This allows for a maximum data rate of 6400 MT
Megatransfer

Transfer or the more common derivatives Gigatransfer and Megatransfer are terms used in computer technology, referring to a number of data transfers ....
/s when running at 3.2 GHz. The operating frequency is auto-negotiated.

HyperTransport supports an auto-negotiated bit width, ranging from two- to 32-link interconnects. The full-width, full-speed, 32-bit interconnect has a transfer rate of 25.6 GB
Gigabyte

Gigabyte is an SI prefix-multiple of the unit byte for Computer data storage. Since the giga- prefix means 109, gigabyte means 1,000,000,000 bytes ....
/s (3.2 GHz/link * 2 bits/Hz * 32 links * 1 Byte / 8 bits) per direction, or 51.2 GB/s aggregated bandwidth per link, making it faster than any existing bus standard for PC workstations and servers (such as Intel sponsored PCI Express) as well as making it faster than most bus standards for high-performance computing and networking. Links of various widths can be mixed together in a single system (for example, one 16-link interconnect to another CPU and one 8-link interconnect to a peripheral device), which allows for a wider interconnect between CPU
Central processing unit

A central processing unit is an electronic circuit that can execute computer programs. This broad definition can easily be applied to many early computers that existed long before the term "CPU" ever came into widespread usage....
s, and a lower-speed interconnect to peripheral
Peripheral

A peripheral is a device attached to a host computer behind the chipset whose primary functionality is dependent upon the host, and can therefore be considered as expanding the hosts capabilities, while not forming part of the system's core computer architecture....
s as appropriate. It also supports link splitting, where a single 16-link interconnect can be divided into two 8-link interconnects. The technology also typically has lower latency than other solutions due to its lower overhead.

Electrically, HyperTransport is similar to Low Voltage Differential Signaling
Low voltage differential signaling

Low-voltage differential signaling, or LVDS, is an electrical signaling system that can run at very high speeds over inexpensive twisted-pair copper cables....
 (LVDS) operating at 1.2 V. HyperTransport 2.0 added post-cursor transmitter deemphasis
Deemphasis

In telecommunication, deemphasis is a system process designed to decrease, within a band of frequencies, the magnitude of some frequencies with respect to the magnitude of other frequencies in order to improve the overall signal-to-noise ratio by minimizing the adverse effects of such phenomena as attenuation differences or saturation of re...
. HyperTransport 3.0 added scrambling and receiver phase alignment as well as optional transmitter pre-cursor deemphasis.

Packet Oriented

HyperTransport is packet-based, where each packet consists of a set of 32-bit
32-bit

The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295 or -2,147,483,648 through 2,147,483,647 using two's complement encoding....
 words, regardless of the physical width of the link. The first word in a packet always contains a command field. Many packets contains a 40-bit address. An additional 32-bit control packet is prepended when 64-bit addressing is required. The data payload is sent after the control packet. Transfers are always padded to a multiple of 32 bits, regardless of their actual length.

HyperTransport packets enter the interconnect in segments known as bit times. The number of bit times required depends on the link width. HyperTransport also supports system management messaging, signaling interrupts, issuing probes to adjacent devices or processors, I/O
I/O

I/O may refer to:* Input/output, a system of communication for information processing systems* The input-output model, an economic model of flow prediction between sectors...
 transactions, and general data transactions. There are two kinds of write commands supported - posted and non-posted. Posted writes do not require a response from the target. This is usually used for high bandwidth devices such as Uniform Memory Access
Uniform Memory Access

Uniform Memory Access is a shared memory architecture used in parallel computers.All the processors in the UMA model share the physical memory uniformly....
 traffic or Direct memory access
Direct memory access

Direct memory access is a feature of modern computers and microprocessors that allows certain hardware subsystems within the computer to access system Computer storage for reading and/or writing independently of the central processing unit....
 transfers. Non-posted writes require a response from the receiver in the form of a "target done". Reads also cause the receiver to generate a read response. HyperTransport supports the PCI consumer-producer ordering model.

Power Managed

HyperTransport also facilitates power management
Power management

Power management is a feature of some electrical appliances, especially photocopying, computer and computer peripherals such as Computer display and Computer printer, that turns off the power or switches the system to a low-power state when inactive....
 as it is compliant with the Advanced Configuration and Power Interface
Advanced Configuration and Power Interface

The Advanced Configuration and Power Interface specification is an open standard for unified operating system-centric device configuration and power management....
 specification. This means that changes in processor sleep states (C states) can signal changes in device states (D states), e.g. powering off disks when the CPU goes to sleep. HyperTransport 3.0 added further capabilities to allow a centralized power management controller to implement power management policies.

Applications for HyperTransport


Front-Side Bus Replacement

The primary use for HyperTransport is to replace the front-side bus, which is currently different for every type of machine. For instance, a Pentium
Pentium

Introduced on March 22, 1993, the original Pentium was the first superscalar x86 architecture microprocessor. Its fifth-generation x86 microarchitecture was a direct extension of the 80486 architecture with dual integer pipeline s, a faster FPU unit, wider data bus, and features for further reduced address calculation latency....
 cannot be plugged into a PCI Express
PCI Express

Peripheral Component Interconnect Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI Local Bus, PCI-X, and Accelerated Graphics Port standards....
 bus. In order to expand the system, the proprietary front-side bus must connect through adapters for the various standard buses, like AGP
Accelerated Graphics Port

The Accelerated Graphics Port is a high-speed point-to-point channel for attaching a :Category:Graphics cards to a computer's motherboard, primarily to assist in the acceleration of 3D computer graphics....
 or PCI Express. These are typically included in the respective controller functions, namely the northbridge
Northbridge (computing)

The northbridge, also known as a memory controller hub or an integrated memory controller in Intel systems , is one of the two chips in the core logic chipset on a PC motherboard, the other being the Southbridge ....
 and southbridge
Southbridge (computing)

The Southbridge, also known as an Input/output Controller Hub or a Platform Controller Hub in Intel systems , is a chip that implements the "slower" capabilities of the motherboard in a northbridge/southbridge chipset computer architecture....
.

In contrast, HyperTransport is an open specification, published by a multi-company consortium. A single HyperTransport adapter chip will work with a wide spectrum of HyperTransport enabled microprocessors. For example, Broadcom HT-1000 and HT-2000 server controller devices can work with many different HyperTransport enabled microprocessors.

AMD uses HyperTransport as the Front-Side Bus
Front side bus

In personal computers, the Front Side Bus is the bus that carries data between the central processing unit and the Northbridge .Depending on the processor used, some computers may also have a back side bus that connects the CPU to the CPU cache....
 in their Opteron
Opteron

The Opteron is Advanced Micro Devices's x86 server Central processing unit line, and was the first processor to implement the AMD64 instruction set architecture ....
, Athlon 64
Athlon 64

The Athlon 64 is an eighth-generation, AMD64-architecture microprocessor produced by AMD, released on September 23, 2003. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP....
, Sempron 64, Turion 64
Turion 64

Turion 64 is the brand name AMD applies to its 64-bit low-consumption Central Processing Unit codenamed K8L. The Turion 64 and Turion 64 X2 processors compete with Intel's mobile processors, initially the Pentium M and currently the Intel Core and Intel Core 2 processors....
, and Phenom
Phenom (processor)

Phenom is the Advanced Micro Devices desktop processor line based on the AMD K10 microarchitecture, or Family 10h Processors, as AMD calls them....
 families of microprocessors.

Multiprocessor interconnect

Another use for HyperTransport is as an interconnect for NUMA
Non-Uniform Memory Access

Non-Uniform Memory Access or Non-Uniform Memory Architecture is a computer storage design used in multiprocessors, where the memory access time depends on the memory location relative to a processor....
 multiprocessor computers. AMD uses HyperTransport with a proprietary cache coherency
Cache coherency

In computing, cache coherence refers to the integrity of data stored in local caches of a shared resource. Cache coherence is a special case of memory coherence....
 extension as part of their Direct Connect Architecture
Direct Connect Architecture

The Direct Connect Architecture is the I/O architecture of the Athlon 64 X2, Opteron, and Phenom microprocessors from AMD. It consists of the combination of three elements:...
 in their Opteron
Opteron

The Opteron is Advanced Micro Devices's x86 server Central processing unit line, and was the first processor to implement the AMD64 instruction set architecture ....
 and Athlon 64 FX (Dual Socket Direct Connect (DSDC) Architecture) line of processors. The HORUS interconnect
AMD Horus

The Horus system, designed by Newisys for AMD, was created to enable AMD Opteron machines to extend beyond the current limit of 8-way architectures....
 from Newisys extends this concept to larger clusters. The Aqua device from 3Leaf Systems virtualizes and interconnects CPUs, memory, and I/O.

Router or Switch Bus Replacement

HyperTransport can also be used as a bus in router
Router

A router is a Computer network device whose software and hardware are usually tailored to the tasks of routing and forwarding information. For example, on the Internet, information is directed to various paths by routers....
s and switches
Network switch

A network switch is a computer networking device that connects computer network Network segment.The term commonly refers to a Network bridge that processes and routes data at the Data link layer of the OSI model....
. Routers and switches have multiple network interfaces and data has to be forwarded between these ports as fast as possible e.g. a four port 100 Mbit
Megabit

A megabit is a unit of Computer data storage, abbreviated Mbit .1 megabit = 106 = 1,000,000 bits which is equal to 125,000 bytes....
/s Ethernet
Ethernet

Ethernet is a family of Data frame-based computer networking technologies for local area networks . The name comes from the physical concept of the Luminiferous aether....
 router needs a maximum 800 Mbit/s of internal bandwidth (100 Mbit/s * 4 ports * 2 directions). HyperTransport greatly exceeds the bandwidth needed for this application.

Co-processor interconnect

The issue of latency and bandwidth between CPUs and co-processors has usually been the major stumbling block to their practical implementation. Recently, co-processors such as FPGAs have appeared which can access the HyperTransport bus and become first-class citizens on the motherboard. Current generation FPGAs from both of the main manufacturers (Altera
Altera

Altera Corporation are a major manufacturer of high-end PLDs . Altera's main products are the Cyclone and Stratix series of FPGAs , the MAX series of CPLDs , the Hardcopy series of structured ASICs and the Quartus II software....
 and Xilinx
Xilinx

Xilinx, Inc. is the world?s largest supplier of programmable logic devices, the inventor of the field programmable gate array and the first semiconductor company with a fabless manufacturing model....
) can directly support the HyperTransport interface and have IP Cores
Semiconductor intellectual property core

In electronic design a semiconductor intellectual property core, IP block, IP core, or logic core is a reusable unit of logic, cell, or chip layout design and is also the intellectual property of one party....
 available. Companies such as XtremeData, Inc. and DRC take these FPGAs (Xilinx in DRC's case) and create a module that allows FPGAs to be plugged directly into the Opteron socket.

AMD started an initiative named Torrenza
Torrenza

Torrenza is an initiative announced by Advanced Micro Devices to improve support for the integration of specialized coprocessors in systems based on AMD Opteron microprocessors....
 in September 21 2006 to further promote the usage of HyperTransport for plug-in cards and coprocessors. This initiative opened their "Socket F" to plug-in boards such as those from XtremeData and DRC.

Add-on card connector (HTX and HTX3)

A connector specification that allows a slot-based peripheral to have direct connection to a microprocessor using a HyperTransport interface was released by the HyperTransport Consortium. It is known as HyperTransport eXpansion (HTX). Using a rotated instance of the same mechanical connector as a 16-lane PCI-Express slot (plus an x1 connector for power pins), HTX allows plug-in cards to be developed which support direct access to a CPU and DMA
Direct memory access

Direct memory access is a feature of modern computers and microprocessors that allows certain hardware subsystems within the computer to access system Computer storage for reading and/or writing independently of the central processing unit....
 access to the system RAM. The initial card for this slot was the QLogic InfiniPath InfiniBand HCA. IBM and HP, among others, have released HTX compliant systems.

The original HTX standard is limited to 16 bits and 800 MHz.

In August, 2008, the HyperTransport Consortium released HTX3, which extends the clock rate of HTX to 2.6 GHz (5.2 GT/s, 10.7 GTi, 5.2 real GHz data speed, 3 MT/s edit rate) and retains backwards compatibility.

Testing

The "DUT" test connector is defined to enable standized functional test system interconnection.

Implementations

  • AMD AMD64 and Direct Connect Architecture
    Direct Connect Architecture

    The Direct Connect Architecture is the I/O architecture of the Athlon 64 X2, Opteron, and Phenom microprocessors from AMD. It consists of the combination of three elements:...
     based CPUs
    Central processing unit

    A central processing unit is an electronic circuit that can execute computer programs. This broad definition can easily be applied to many early computers that existed long before the term "CPU" ever came into widespread usage....
    .
  • SiByte MIPS
    MIPS architecture

    MIPS is a RISC instruction set architecture developed by MIPS Technologies . In the mid to late 1990s, it was estimated that one in three RISC microprocessors produced were MIPS implementations....
     cpus from Broadcom
    Broadcom

    Broadcom Corporation is an United States supplier of integrated circuits for broadband communications. Founded in 1991 by Henry Samueli and Henry T....
  • PMC-Sierra
    PMC-Sierra

    PMC-Sierra is a fabless semiconductor company which develops and sells devices into the communications, storage, printing, and embedded computing marketplaces....
     RM9000X2 MIPS
    MIPS architecture

    MIPS is a RISC instruction set architecture developed by MIPS Technologies . In the mid to late 1990s, it was estimated that one in three RISC microprocessors produced were MIPS implementations....
     CPU
  • ht_tunnel from OpenCores
    OpenCores

    OpenCores is a loose community of people who are interested in developing digital open source hardware through electronic design automation, with a similar ethos to the free software movement....
     project (MPL licence)
  • ATI
    ATI Technologies

    ATI Technologies Inc. was a major designer and supplier of graphics processing units and motherboard chipsets. In 2006, the company was acquired by Advanced Micro Devices and was renamed the AMD Graphics Product Group, although the ATI brand was retained for graphics cards....
     Radeon Xpress 200 for AMD Processor
  • NVIDIA
    NVIDIA

    Nvidia is a multinational corporation specializing in the manufacture of graphics processing unit technologies for workstations, desktop computers, and mobile devices....
     nForce chipsets
    • nForce Professional MCPs (Media and Communication Processor)
    • nForce 4
      NForce4

      The nForce4 is a motherboard chipset released by Nvidia in October, 2004. The chipset supports AMD64 processors and Intel Corporation Pentium 4 Socket T processors....
       series
    • nForce 500 series
      NForce 500

      The nForce 500 is a motherboard chipset series and the successor to the nForce4 series. It was revealed by NVIDIA on 2006-03-07 and released on 2006-05-23....
    • nForce 600 series
      NForce 600

      The nForce 600 chipset was released in the first half of November 2006, coinciding with the GeForce 8 series launch on November 8, 2006. The nForce 600 supports Intel's LGA775 socket and Advanced Micro Devices's AMD Quad FX platform and replaces the nForce 500 series....
    • nForce 700 series
      NForce 700

      The nForce 700 is a chipset series designed by Nvidia first released in December 2007. The series supports both Intel Core 2 and Advanced Micro Devices Phenom processors, and replaces the nForce 600 series chipsets....
  • ServerWorks (now Broadcom
    Broadcom

    Broadcom Corporation is an United States supplier of integrated circuits for broadband communications. Founded in 1991 by Henry Samueli and Henry T....
    ) HT-2000 HyperTransport SystemI/O Controller
  • The IBM
    IBM

    International Business Machines Corporation, abbreviated IBM and nicknamed "Big Blue" , is a multinational corporation computer technology and consulting corporation headquartered in Armonk, New York, New York, United States....
     CPC925 and CPC945 PowerPC 970 northbridges
  • Raza Thread Processors
  • Several open source cores from the HyperTransport Center of Excellence


HyperTransport frequency specifications

HyperTransport
Version		 Year Max. HT Frequency Max. Link Width Max. Aggregate Bandwidth
(bi-directional)		 Max. Bandwidth at
16-Bit unidirectional		 Max. Bandwidth at
32-Bit unidirectional*
1.0 2001 800 MHz 32 Bit 12.8 GB/s 3.2 GB/s 6.4 GB/s
1.1 2002 800 MHz 32 Bit 12.8 GB/s 3.2 GB/s 6.4 GB/s
2.0 2004 1.4 GHz 32 Bit 22.4 GB/s 5.6 GB/s 11.2 GB/s
3.0 2006 2.6 GHz 32 Bit 41.6 GB/s 10.4 GB/s 20.8 GB/s
3.1 2008 3.2 GHz 32 Bit 51.2 GB/s 12.8 GB/s 25.6 GB/s


  • AMD Opterons, Athlon64s and later use 16-bit links. Common speeds for these processor interlinks are 800 MHz to 1 GHz (older and multiprocessor systems) and 2 to 2.6 GHz (newer uniprocessors on AM2+ links). While Hypertransport itself is capable of 32-bit links, it is not currently utilized by any AMD processors.


Name

There has been some marketing confusion between the use of HT referring to HyperTransport and the later use of HT to refer to Intel's Hyper-Threading
Hyper-threading

Hyper-threading is Intel trademarked term for its simultaneous multithreading implementation in their Pentium 4, Intel Atom, and Intel Core i7 CPUs....
 feature on some Pentium 4
Pentium 4

The Pentium 4 brand refers to Intel's line of single-core mainstream Desktop computer and laptop central processing units introduced on November 20, 2000 ....
 based and the newer Intel Core i7
Intel Core i7

Intel Core i7 is a family of three Intel desktop x86-64 processors, the first processors released using the Intel Nehalem and the successor to the Intel Core 2 family....
 microprocessors. Hyper-Threading is officially known as Hyper-Threading Technology (HTT) or HT-Technology. Because of this potential for confusion, the HyperTransport Consortium always uses the written out form: "HyperTransport".

See also

  • Elastic interface bus
    Elastic interface bus

    Elastic Interface buses can be generalized as bus which are high speed interfaces that have Clock signal sent with data. All of the data bits are aligned to the clock to be able to latch the data at these high speeds....
  • Fibre Channel
    Fibre Channel

    Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the Technical Committee T11 of the InterNational Committee for Information Technology Standards , an American National Standards Institute ?accredited standards committee....
  • Front side bus
    Front side bus

    In personal computers, the Front Side Bus is the bus that carries data between the central processing unit and the Northbridge .Depending on the processor used, some computers may also have a back side bus that connects the CPU to the CPU cache....
  • Intel QuickPath Interconnect
  • List of device bandwidths
    List of device bandwidths

    This is a list of device bandwidths: the net bit rate of some computer devices employing methods of data transport is quantified in units of kilobits per second , megabits per second , or gigabits per second as appropriate....
  • PCI Express
    PCI Express

    Peripheral Component Interconnect Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI Local Bus, PCI-X, and Accelerated Graphics Port standards....
  • RapidIO
    RapidIO

    The RapidIO architecture is a high-performance packet-switched, Electrical connection technology for interconnecting Integrated circuit on a Printed circuit board, and also circuit boards to each other using a backplane....


External links