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A multi-core processor is a
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
on a single
integrated circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
with two or more separate
processing units, called cores, each of which reads and executes
program instructions. The instructions are ordinary
CPU instructions
In computer programming, machine code is any low-level programming language, consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Each instruction causes the CPU to perform a very ...
(such as add, move data, and branch) but the single processor can run instructions on separate cores at the same time, increasing overall speed for programs that support
multithreading or other
parallel computing
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different fo ...
techniques. Manufacturers typically integrate the cores onto a single integrated circuit
die
Die, as a verb, refers to death, the cessation of life.
Die may also refer to:
Games
* Die, singular of dice, small throwable objects used for producing random numbers
Manufacturing
* Die (integrated circuit), a rectangular piece of a semicondu ...
(known as a chip multiprocessor or CMP) or onto multiple dies in a single
chip package
Integrated circuits are put into protective packages to allow easy handling and assembly onto printed circuit boards and to protect the devices from damage. A very large number of different types of package exist. Some package types have standa ...
. The microprocessors currently used in almost all personal computers are multi-core.
A multi-core processor implements
multiprocessing
Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. There ar ...
in a single physical package. Designers may couple cores in a multi-core device tightly or loosely. For example, cores may or may not share
caches, and they may implement
message passing
In computer science, message passing is a technique for invoking behavior (i.e., running a program) on a computer. The invoking program sends a message to a process (which may be an actor or object) and relies on that process and its supporting i ...
or
shared-memory
In computer science, shared memory is random-access memory, memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Shared memory is an efficient means of pass ...
inter-core communication methods. Common
network topologies used to interconnect cores include
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
,
ring
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
, two-dimensional
mesh
A mesh is a barrier made of connected strands of metal, fiber, or other flexible or ductile materials. A mesh is similar to a web or a net in that it has many attached or woven strands.
Types
* A plastic mesh may be extruded, oriented, ex ...
, and
crossbar
Crossbar may refer to:
Structures
* Latch (hardware), a post barring a door
* Top tube of a bicycle frame
* Crossbar, the horizontal member of various sports goals
* Crossbar, a horizontal member of an electricity pylon
Other
* In electronic ...
. Homogeneous multi-core systems include only identical cores;
heterogeneous
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...
multi-core systems have cores that are not identical (e.g.
big.LITTLE
ARM big.LITTLE is a heterogeneous computing architecture developed by ARM Holdings, coupling relatively battery-saving and slower processor cores (''LITTLE'') with relatively more powerful and power-hungry ones (''big''). Typically, only one "s ...
have heterogeneous cores that share the same
instruction set
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ' ...
, while
AMD Accelerated Processing Unit
AMD Accelerated Processing Unit (APU), formerly known as Fusion, is a series of 64-bit microprocessors from Advanced Micro Devices (AMD), combining a general-purpose AMD64 central processing unit ( CPU) and integrated graphics processing unit ...
s have cores that do not share the same instruction set). Just as with single-processor systems, cores in multi-core systems may implement architectures such as
VLIW
Very long instruction word (VLIW) refers to instruction set architectures designed to exploit instruction level parallelism (ILP). Whereas conventional central processing units (CPU, processor) mostly allow programs to specify instructions to exe ...
,
superscalar
A superscalar processor is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. In contrast to a scalar processor, which can execute at most one single instruction per clock cycle, a sup ...
,
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
, or
multithreading.
Multi-core processors are widely used across many application domains, including
general-purpose,
embedded,
network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematics
...
,
digital signal processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
(DSP), and
graphics
Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture ...
(GPU). Core count goes up to even dozens, and for specialized chips over 10,000,
and in
supercomputer
A supercomputer is a computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second ( FLOPS) instead of million instructions ...
s (i.e. clusters of chips) the count can go over 10 million (and in
one case up to 20 million processing elements total in addition to host processors).
The improvement in performance gained by the use of a multi-core processor depends very much on the
software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
algorithms used and their implementation. In particular, possible gains are limited by the fraction of the software that can
run in parallel simultaneously on multiple cores; this effect is described by
Amdahl's law
In computer architecture, Amdahl's law (or Amdahl's argument) is a formula which gives the theoretical speedup in latency of the execution of a task at fixed workload that can be expected of a system whose resources are improved. It states that ...
. In the best case, so-called
embarrassingly parallel
In parallel computing, an embarrassingly parallel workload or problem (also called embarrassingly parallelizable, perfectly parallel, delightfully parallel or pleasingly parallel) is one where little or no effort is needed to separate the problem i ...
problems may realize speedup factors near the number of cores, or even more if the problem is split up enough to fit within each core's cache(s), avoiding use of much slower main-system memory. Most applications, however, are not accelerated as much unless programmers invest effort in
refactoring
In computer programming and software design, code refactoring is the process of restructuring existing computer code—changing the '' factoring''—without changing its external behavior. Refactoring is intended to improve the design, structure ...
.
The parallelization of software is a significant ongoing topic of research. Cointegration of multiprocessor applications provides flexibility in network architecture design. Adaptability within parallel models is an additional feature of systems utilizing these protocols.
Terminology
The terms ''multi-core'' and ''dual-core'' most commonly refer to some sort of
central processing unit
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...
(CPU), but are sometimes also applied to
digital signal processor
A digital signal processor (DSP) is a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing. DSPs are fabricated on MOS integrated circuit chips. They are widely used in audio si ...
s (DSP) and
system on a chip
A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...
(SoC). The terms are generally used only to refer to multi-core microprocessors that are manufactured on the ''same'' integrated circuit
die
Die, as a verb, refers to death, the cessation of life.
Die may also refer to:
Games
* Die, singular of dice, small throwable objects used for producing random numbers
Manufacturing
* Die (integrated circuit), a rectangular piece of a semicondu ...
; separate microprocessor dies in the same package are generally referred to by another name, such as ''
multi-chip module
A multi-chip module (MCM) is generically an electronic assembly (such as a package with a number of conductor terminals or "pins") where multiple integrated circuits (ICs or "chips"), semiconductor dies and/or other discrete components are int ...
''. This article uses the terms "multi-core" and "dual-core" for CPUs manufactured on the ''same'' integrated circuit, unless otherwise noted.
In contrast to multi-core systems, the term ''multi-CPU'' refers to multiple physically separate processing-units (which often contain special circuitry to facilitate communication between each other).
The terms ''many-core'' and ''massively multi-core'' are sometimes used to describe multi-core architectures with an especially high number of cores (tens to thousands).
Some systems use many
soft microprocessor
A soft microprocessor (also called softcore microprocessor or a soft processor) is a microprocessor core that can be wholly implemented using logic synthesis. It can be implemented via different semiconductor devices containing programmable logic ...
cores placed on a single
FPGA
A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware de ...
. Each "core" can be considered a "
semiconductor intellectual property core
In electronic design, a semiconductor intellectual property core (SIP core), IP core, or IP block is a reusable unit of logic, cell, or integrated circuit layout design that is the intellectual property of one party. IP cores can be licensed to ...
" as well as a CPU core.
Development
While manufacturing technology improves, reducing the size of individual gates, physical limits of
semiconductor
A semiconductor is a material which has an electrical resistivity and conductivity, electrical conductivity value falling between that of a electrical conductor, conductor, such as copper, and an insulator (electricity), insulator, such as glas ...
-based
microelectronics
Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-sc ...
have become a major design concern. These physical limitations can cause significant heat dissipation and data synchronization problems. Various other methods are used to improve CPU performance. Some ''
instruction-level parallelism
Instruction-level parallelism (ILP) is the parallel or simultaneous execution of a sequence of instructions in a computer program. More specifically ILP refers to the average number of instructions run per step of this parallel execution.
Discu ...
'' (ILP) methods such as
superscalar
A superscalar processor is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. In contrast to a scalar processor, which can execute at most one single instruction per clock cycle, a sup ...
pipelining are suitable for many applications, but are inefficient for others that contain difficult-to-predict code. Many applications are better suited to ''
thread-level parallelism'' (TLP) methods, and multiple independent CPUs are commonly used to increase a system's overall TLP. A combination of increased available space (due to refined manufacturing processes) and the demand for increased TLP led to the development of multi-core CPUs.
Commercial incentives
Several business motives drive the development of multi-core architectures. For decades, it was possible to improve performance of a CPU by shrinking the area of the integrated circuit (IC), which reduced the cost per device on the IC. Alternatively, for the same circuit area, more transistors could be used in the design, which increased functionality, especially for
complex instruction set computing
A complex instruction set computer (CISC ) is a computer architecture in which single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or are capable of multi-step o ...
(CISC) architectures.
Clock rate
In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a processor can generate pulses, which are used to synchronize the operations of its components, and is used as an indicator of the pr ...
s also increased by orders of magnitude in the decades of the late 20th century, from several megahertz in the 1980s to several gigahertz in the early 2000s.
As the rate of clock speed improvements slowed, increased use of parallel computing in the form of multi-core processors has been pursued to improve overall processing performance. Multiple cores were used on the same CPU chip, which could then lead to better sales of CPU chips with two or more cores. For example, Intel has produced a 48-core processor for research in cloud computing; each core has an
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...
architecture.
Technical factors
Since computer manufacturers have long implemented
symmetric multiprocessing
Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ...
(SMP) designs using discrete CPUs, the issues regarding implementing multi-core processor architecture and supporting it with software are well known.
Additionally:
* Using a proven processing-core design without architectural changes reduces design risk significantly.
* For general-purpose processors, much of the motivation for multi-core processors comes from greatly diminished gains in processor performance from increasing the
operating frequency
In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a Microprocessor, processor can generate Clock signal, pulses, which are used to Synchronization (computer science), synchronize the op ...
. This is due to three primary factors:
*# The ''memory wall''; the increasing gap between processor and memory speeds. This, in effect, pushes for cache sizes to be larger in order to mask the latency of memory. This helps only to the extent that memory bandwidth is not the bottleneck in performance.
*# The ''ILP wall''; the increasing difficulty of finding enough
parallelism in a single instruction stream to keep a high-performance single-core processor busy.
*# The ''power wall''; the trend of consuming exponentially increasing power (and thus also generating exponentially increasing heat) with each factorial increase of operating frequency. This increase can be mitigated by "
shrinking" the processor by using smaller traces for the same logic. The ''power wall'' poses manufacturing, system design and deployment problems that have not been justified in the face of the diminished gains in performance due to the ''memory wall'' and ''ILP wall''.
In order to continue delivering regular performance improvements for general-purpose processors, manufacturers such as
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
and
AMD
Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...
have turned to multi-core designs, sacrificing lower manufacturing-costs for higher performance in some applications and systems. Multi-core architectures are being developed, but so are the alternatives. An especially strong contender for established markets is the further integration of peripheral functions into the chip.
Advantages
The proximity of multiple CPU cores on the same die allows the
cache coherency
In computer architecture, cache coherence is the uniformity of shared resource data that ends up stored in multiple local caches. When clients in a system maintain caches of a common memory resource, problems may arise with incoherent data, whi ...
circuitry to operate at a much higher clock rate than what is possible if the signals have to travel off-chip. Combining equivalent CPUs on a single die significantly improves the performance of
cache snoop (alternative:
Bus snooping Bus snooping or bus sniffing is a scheme by which a coherency controller (snooper) in a cache (a snoopy cache) monitors or snoops the bus transactions, and its goal is to maintain a cache coherency in distributed shared memory systems. A cache cont ...
) operations. Put simply, this means that
signals
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' ...
between different CPUs travel shorter distances, and therefore those signals
degrade
Degradation may refer to:
Science
* Degradation (geology), lowering of a fluvial surface by erosion
* Degradation (telecommunications), of an electronic signal
* Biodegradation of organic substances by living organisms
* Environmental degradation ...
less. These higher-quality signals allow more data to be sent in a given time period, since individual signals can be shorter and do not need to be repeated as often.
Assuming that the die can physically fit into the package, multi-core CPU designs require much less
printed circuit board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
(PCB) space than do multi-chip SMP designs. Also, a dual-core processor uses slightly less power than two coupled single-core processors, principally because of the decreased power required to drive signals external to the chip. Furthermore, the cores share some circuitry, like the L2 cache and the interface to the
front-side bus
A front-side bus (FSB) is a computer communication interface (bus) that was often used in Intel-chip-based computers during the 1990s and 2000s. The EV6 bus served the same function for competing AMD CPUs. Both typically carry data between the ...
(FSB). In terms of competing technologies for the available silicon die area, multi-core design can make use of proven CPU core library designs and produce a product with lower risk of design error than devising a new wider-core design. Also, adding more cache suffers from diminishing returns.
Multi-core chips also allow higher performance at lower energy. This can be a big factor in mobile devices that operate on batteries. Since each core in a multi-core CPU is generally more energy-efficient, the chip becomes more efficient than having a single large monolithic core. This allows higher performance with less energy. A challenge in this, however, is the additional overhead of writing parallel code.
Disadvantages
Maximizing the usage of the computing resources provided by multi-core processors requires adjustments both to the
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
(OS) support and to existing application software. Also, the ability of multi-core processors to increase application performance depends on the use of multiple threads within applications.
Integration of a multi-core chip can lower the chip production yields. They are also more difficult to manage thermally than lower-density single-core designs. Intel has partially countered this first problem by creating its quad-core designs by combining two dual-core ones on a single die with a unified cache, hence any two working dual-core dies can be used, as opposed to producing four cores on a single die and requiring all four to work to produce a quad-core CPU. From an architectural point of view, ultimately, single CPU designs may make better use of the silicon surface area than multiprocessing cores, so a development commitment to this architecture may carry the risk of obsolescence. Finally, raw processing power is not the only constraint on system performance. Two processing cores sharing the same system bus and memory bandwidth limits the real-world performance advantage. In a 2009 report, Dr Jun Ni showed that if a single core is close to being memory-bandwidth limited, then going to dual-core might give 30% to 70% improvement; if memory bandwidth is not a problem, then a 90% improvement can be expected; however,
Amdahl's law
In computer architecture, Amdahl's law (or Amdahl's argument) is a formula which gives the theoretical speedup in latency of the execution of a task at fixed workload that can be expected of a system whose resources are improved. It states that ...
makes this claim dubious.
It would be possible for an application that used two CPUs to end up running faster on a single-core one if communication between the CPUs was the limiting factor, which would count as more than 100% improvement.
Hardware
Trends
The trend in processor development has been towards an ever-increasing number of cores, as processors with hundreds or even thousands of cores become theoretically possible. In addition, multi-core chips mixed with
simultaneous multithreading
Simultaneous multithreading (SMT) is a technique for improving the overall efficiency of superscalar CPUs with hardware multithreading. SMT permits multiple independent threads of execution to better use the resources provided by modern process ...
, memory-on-chip, and special-purpose
"heterogeneous" (or asymmetric) cores promise further performance and efficiency gains, especially in processing multimedia, recognition and networking applications. For example, a
big.LITTLE
ARM big.LITTLE is a heterogeneous computing architecture developed by ARM Holdings, coupling relatively battery-saving and slower processor cores (''LITTLE'') with relatively more powerful and power-hungry ones (''big''). Typically, only one "s ...
core includes a high-performance core (called 'big') and a low-power core (called 'LITTLE'). There is also a trend towards improving energy-efficiency by focusing on performance-per-watt with advanced fine-grain or ultra fine-grain
power management
Power management is a feature of some electrical appliances, especially copiers, computers, computer CPUs, computer GPUs and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power stat ...
and dynamic
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...
and
frequency scaling
In computer architecture, frequency scaling (also known as frequency ramping) is the technique of increasing a processor's frequency so as to enhance the performance of the system containing the processor in question. Frequency ramping was the dom ...
(i.e.
laptop
A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper li ...
computers and
portable media player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored o ...
s).
Chips designed from the outset for a large number of cores (rather than having evolved from single core designs) are sometimes referred to as
manycore
Manycore processors are special kinds of multi-core processors designed for a high degree of parallel processing, containing numerous simpler, independent processor cores (from a few tens of cores to thousands or more). Manycore processors are use ...
designs, emphasising qualitative differences.
Architecture
The composition and balance of the cores in multi-core architecture show great variety. Some architectures use one core design repeated consistently ("homogeneous"), while others use a mixture of different cores, each optimized for a different, "
heterogeneous
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...
" role.
How multiple cores are implemented and integrated significantly affects both the developer's programming skills and the consumer's expectations of apps and interactivity versus the device. A device advertised as being octa-core will only have independent cores if advertised as ''True Octa-core'', or similar styling, as opposed to being merely two sets of quad-cores each with fixed clock speeds.
The article "CPU designers debate multi-core future" by Rick Merritt, EE Times 2008, includes these comments:
Software effects
An outdated version of an anti-virus application may create a new thread for a scan process, while its
GUI
The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...
thread waits for commands from the user (e.g. cancel the scan). In such cases, a multi-core architecture is of little benefit for the application itself due to the single thread doing all the heavy lifting and the inability to balance the work evenly across multiple cores. Programming truly multithreaded code often requires complex co-ordination of threads and can easily introduce subtle and difficult-to-find bugs due to the interweaving of processing on data shared between threads (see
thread-safety Thread safety is a computer programming concept applicable to multi-threaded code. Thread-safe code only manipulates shared data structures in a manner that ensures that all threads behave properly and fulfill their design specifications without uni ...
). Consequently, such code is much more difficult to debug than single-threaded code when it breaks. There has been a perceived lack of motivation for writing consumer-level threaded applications because of the relative rarity of consumer-level demand for maximum use of computer hardware. Also, serial tasks like decoding the
entropy encoding
In information theory, an entropy coding (or entropy encoding) is any lossless data compression method that attempts to approach the lower bound declared by Shannon's source coding theorem, which states that any lossless data compression method ...
algorithms used in
video codec
A video codec is software or hardware that compresses and decompresses digital video. In the context of video compression, ''codec'' is a portmanteau of ''encoder'' and ''decoder'', while a device that only compresses is typically called an '' ...
s are impossible to parallelize because each result generated is used to help create the next result of the entropy decoding algorithm.
Given the increasing emphasis on multi-core chip design, stemming from the grave thermal and power consumption problems posed by any further significant increase in processor clock speeds, the extent to which software can be multithreaded to take advantage of these new chips is likely to be the single greatest constraint on computer performance in the future. If developers are unable to design software to fully exploit the resources provided by multiple cores, then they will ultimately reach an insurmountable performance ceiling.
The telecommunications market had been one of the first that needed a new design of parallel datapath packet processing because there was a very quick adoption of these multiple-core processors for the datapath and the control plane. These MPUs are going to replace the traditional Network Processors that were based on proprietary
microcode
In processor design, microcode (μcode) is a technique that interposes a layer of computer organization between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. Microcode is a laye ...
or
picocode
In processor design, microcode (μcode) is a technique that interposes a layer of computer organization between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. Microcode is a lay ...
.
Parallel programming
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different for ...
techniques can benefit from multiple cores directly. Some existing
parallel programming model
In computing, a parallel programming model is an abstraction of parallel computer architecture, with which it is convenient to express algorithms and their composition in programs. The value of a programming model can be judged on its ''generality ...
s such as
Cilk Plus
Cilk, Cilk++, Cilk Plus and OpenCilk are general-purpose programming languages designed for multithreaded parallel computing. They are based on the C and C++ programming languages, which they extend with constructs to express parallel loop ...
,
OpenMP
OpenMP (Open Multi-Processing) is an application programming interface (API) that supports multi-platform shared-memory multiprocessing programming in C, C++, and Fortran, on many platforms, instruction-set architectures and operating syste ...
,
OpenHMPP
OpenHMPP (HMPP for Hybrid Multicore Parallel Programming) - programming standard for heterogeneous computing. Based on a set of compiler directives, standard is a programming model designed to handle hardware accelerators without the complexity a ...
,
FastFlow, Skandium,
MPI, and
Erlang can be used on multi-core platforms. Intel introduced a new abstraction for C++ parallelism called
TBB. Other research efforts include the
Codeplay Sieve System, Cray's
Chapel
A chapel is a Christian place of prayer and worship that is usually relatively small. The term has several meanings. Firstly, smaller spaces inside a church that have their own altar are often called chapels; the Lady chapel is a common ty ...
, Sun's
Fortress
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ...
, and IBM's
X10.
Multi-core processing has also affected the ability of modern computational software development. Developers programming in newer languages might find that their modern languages do not support multi-core functionality. This then requires the use of
numerical libraries
Numerical may refer to:
* Number
* Numerical digit
* Numerical analysis
Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distin ...
to access code written in languages like
C and
Fortran, which perform math computations faster than newer languages like
C#. Intel's MKL and AMD's
ACML are written in these native languages and take advantage of multi-core processing. Balancing the application workload across processors can be problematic, especially if they have different performance characteristics. There are different conceptual models to deal with the problem, for example using a coordination language and program building blocks (programming libraries or higher-order functions). Each block can have a different native implementation for each processor type. Users simply program using these abstractions and an intelligent compiler chooses the best implementation based on the context.
Managing
concurrency acquires a central role in developing parallel applications. The basic steps in designing parallel applications are:
; Partitioning : The partitioning stage of a design is intended to expose opportunities for parallel execution. Hence, the focus is on defining a large number of small tasks in order to yield what is termed a fine-grained decomposition of a problem.
; Communication : The tasks generated by a partition are intended to execute concurrently but cannot, in general, execute independently. The computation to be performed in one task will typically require data associated with another task. Data must then be transferred between tasks so as to allow computation to proceed. This information flow is specified in the communication phase of a design.
; Agglomeration : In the third stage, development moves from the abstract toward the concrete. Developers revisit decisions made in the partitioning and communication phases with a view to obtaining an algorithm that will execute efficiently on some class of parallel computer. In particular, developers consider whether it is useful to combine, or agglomerate, tasks identified by the partitioning phase, so as to provide a smaller number of tasks, each of greater size. They also determine whether it is worthwhile to replicate data and computation.
; Mapping : In the fourth and final stage of the design of parallel algorithms, the developers specify where each task is to execute. This mapping problem does not arise on uniprocessors or on shared-memory computers that provide automatic task scheduling.
On the other hand, on the
server side
In the client–server model, server-side refers to programs and operations that run on the server. This is in contrast to client-side programs and operations which run on the client.
General concepts
Typically, a server is a computer application ...
, multi-core processors are ideal because they allow many users to connect to a site simultaneously and have independent
threads of execution. This allows for Web servers and application servers that have much better
throughput
Network throughput (or just throughput, when in context) refers to the rate of message delivery over a communication channel, such as Ethernet or packet radio, in a communication network. The data that these messages contain may be delivered ov ...
.
Licensing
Vendors may license some software "per processor". This can give rise to ambiguity, because a "processor" may consist either of a single core or of a combination of cores.
* Initially, for some of its enterprise software,
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...
continued to use a per-
socket
Socket may refer to:
Mechanics
* Socket wrench, a type of wrench that uses separate, removable sockets to fit different sizes of nuts and bolts
* Socket head screw, a screw (or bolt) with a cylindrical head containing a socket into which the hexag ...
licensing system. However, for some software such as
BizTalk Server 2013,
SQL Server 2014, and
Windows Server 2016
Windows Server 2016 is the eighth release of the Windows Server server operating system developed by Microsoft as part of the Windows NT family of operating systems. It was developed concurrently with Windows 10 and is the successor to the Wind ...
, Microsoft has shifted to per-core licensing.
*
Oracle Corporation
Oracle Corporation is an American multinational computer technology corporation headquartered in Austin, Texas. In 2020, Oracle was the third-largest software company in the world by revenue and market capitalization. The company sells da ...
counts an AMD X2 or an Intel dual-core CPU as a single processor but uses other metrics for other types, especially for processors with more than two cores.
Embedded applications
Embedded computing
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as ...
operates in an area of processor technology distinct from that of "mainstream" PCs. The same technological drives towards multi-core apply here too. Indeed, in many cases the application is a "natural" fit for multi-core technologies, if the task can easily be partitioned between the different processors.
In addition, embedded software is typically developed for a specific hardware release, making issues of
software portability
A computer program is said to be portable if there is very low effort required to make it run on different platforms. The pre-requirement for portability is the generalized abstraction between the application logic and system interfaces. When ...
, legacy code or supporting independent developers less critical than is the case for PC or enterprise computing. As a result, it is easier for developers to adopt new technologies and as a result there is a greater variety of multi-core processing architectures and suppliers.
Network processors
, multi-core
network processors
A network processor is an integrated circuit which has a feature set specifically targeted at the Computer networking, networking application domain.
Network processors are typically software programmable devices and would have generic characteris ...
have become mainstream, with companies such as
Freescale Semiconductor
Freescale Semiconductor, Inc. was an American semiconductor manufacturer. It was created by the divestiture of the Semiconductor Products Sector of Motorola in 2004. Freescale focused their integrated circuit products on the automotive, embed ...
,
Cavium Networks
Cavium was a fabless semiconductor company based in San Jose, California, specializing in ARM-based and MIPS-based network, video and security processors and SoCs. The company was co-founded in 2000 by Syed B. Ali and M. Raghib Hussain, who wer ...
,
Wintegra and
Broadcom
Broadcom Inc. is an American designer, developer, manufacturer and global supplier of a wide range of semiconductor and infrastructure software products. Broadcom's product offerings serve the data center, networking, software, broadband, wirel ...
all manufacturing products with eight processors. For the system developer, a key challenge is how to exploit all the cores in these devices to achieve maximum networking performance at the system level, despite the performance limitations inherent in a
symmetric multiprocessing
Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ...
(SMP) operating system. Companies such as
6WIND
6WIND is a virtual networking software company delivering disaggregated and cloud-native solutions to CSPs and enterprises globally. The company is privately held and headquartered in the West Paris area, in Montigny-le-Bretonneux. 6WIND has a gl ...
provide portable packet processing software designed so that the networking data plane runs in a fast path environment outside the operating system of the network device.
Digital signal processing
In
digital signal processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
the same trend applies:
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...
has the three-core TMS320C6488 and four-core TMS320C5441,
Freescale
Freescale Semiconductor, Inc. was an American semiconductor manufacturer. It was created by the divestiture of the Semiconductor Products Sector of Motorola in 2004. Freescale focused their integrated circuit products on the automotive, embed ...
the four-core MSC8144 and six-core MSC8156 (and both have stated they are working on eight-core successors). Newer entries include the Storm-1 family fro
Stream Processors, Incwith 40 and 80 general purpose ALUs per chip, all programmable in C as a SIMD engine and
Picochip with 300 processors on a single die, focused on communication applications.
Heterogeneous systems
In
heterogeneous computing
Heterogeneous computing refers to systems that use more than one kind of processor or cores. These systems gain performance or energy efficiency not just by adding the same type of processors, but by adding dissimilar coprocessors, usually incorp ...
, where a system uses more than one kind of processor or cores, multi-core solutions are becoming more common:
Xilinx
Xilinx, Inc. ( ) was an American technology and semiconductor company that primarily supplied programmable logic devices. The company was known for inventing the first commercially viable field-programmable gate array (FPGA) and creating the fi ...
Zynq UltraScale+ MPSoC has a quad-core ARM Cortex-A53 and dual-core ARM Cortex-R5. Software solutions such as OpenAMP are being used to help with inter-processor communication.
Mobile devices may use the
ARM big.LITTLE architecture.
Hardware examples
Commercial
*
Adapteva
Zero ASIC Corporation, formerly Adapteva, Inc., is a fabless semiconductor company focusing on low power many core microprocessor design. The company was the second company to announce a design with 1,000 specialized processing cores on a single ...
Epiphany, a many-core processor architecture which allows up to 4096 processors on-chip, although only a 16-core version has been commercially produced.
*
Aeroflex Gaisler LEON3, a multi-core
SPARC
SPARC (Scalable Processor Architecture) is a reduced instruction set computer (RISC) instruction set architecture originally developed by Sun Microsystems. Its design was strongly influenced by the experimental Berkeley RISC system developed ...
that also exists in a
fault-tolerant version.
*
Ageia
Ageia, founded in 2002, was a fabless semiconductor company. In 2004, Ageia acquired NovodeX, the company who created PhysX – a Physics Processing Unit chip capable of performing game physics calculations much faster than general purpose CPUs; ...
PhysX
PhysX is an open-source realtime physics engine middleware SDK developed by Nvidia as a part of Nvidia GameWorks software suite.
Initially, video games supporting PhysX were meant to be accelerated by PhysX PPU (expansion cards designed by Ag ...
, a multi-core
physics processing unit
A physics processing unit (PPU) is a dedicated microprocessor designed to handle the calculations of physics, especially in the physics engine of video games. It is an example of hardware acceleration.
Examples of calculations involving a PPU mig ...
.
*
Ambric Am2045, a 336-core Massively Parallel Processor Array (MPPA)
*
AMD
Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...
**
A-Series, dual-, triple-, and quad-core of Accelerated Processor Units (APU).
**
Athlon 64 FX
The Athlon 64 is a ninth-generation, AMD64-architecture microprocessor produced by Advanced Micro Devices (AMD), released on September 23, 2003. It is the third processor to bear the name ''Athlon'', and the immediate successor to the Athlon XP. T ...
and
Athlon 64 X2
The Athlon 64 X2 is the first native dual-core desktop central processing unit (CPU) designed by Advanced Micro Devices (AMD). It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with ano ...
single- and dual-core desktop processors.
**
Athlon II
Athlon II is a family of AMD multi-core 45 nm central processing units, which is aimed at the budget to mid-range market and is a complementary product lineup to the Phenom II.
Features
The Athlon II series is based on the AMD K10 architect ...
, dual-, triple-, and quad-core desktop processors.
**
FX-Series, quad-, 6-, and 8-core desktop processors.
**
Opteron
Opteron is AMD's x86 former server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture (known generically as x86-64 or AMD64). It was released on April 22, 2003, with the ''SledgeHa ...
, single-, dual-, quad-, 6-, 8-, 12-, and 16-core server/workstation processors.
**
Phenom
Phenom may refer to:
* AMD Phenom, the 64-bit AMD desktop processor line based on the K10 microarchitecture
** Phenom II, a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture
* Phenom (electron microscope), a fast elec ...
, dual-, triple-, and quad-core processors.
**
Phenom II
Phenom II is a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture, succeeding the original Phenom. Advanced Micro Devices released the Socket AM2+ version of Phenom II in December 2008, while Socket AM3 versions w ...
, dual-, triple-, quad-, and 6-core desktop processors.
**
Sempron
Sempron has been the marketing name used by AMD for several different budget desktop CPUs, using several different technologies and CPU socket formats. The Sempron replaced the AMD Duron processor and competed against Intel's Celeron series of pr ...
, single-, dual-, and quad-core entry level processors.
**
Turion, single- and dual-core laptop processors.
**
Ryzen
Ryzen ( ) is a brand of multi-core x86-64 microprocessors designed and marketed by AMD for desktop, mobile, server, and embedded platforms based on the Zen microarchitecture. It consists of central processing units (CPUs) marketed for mainst ...
, dual-, quad-, 6-, 8-, 12-, 16-, 24-, 32-, and 64-core desktop, mobile, and embedded platform processors.
**
Epyc
Epyc is a brand of multi-core x86-64 microprocessors designed and sold by AMD, based on the company's Zen microarchitecture. Introduced in June 2017, they are specifically targeted for the server and embedded system markets. Epyc processors share t ...
, quad-, 8-, 12-, 16-, 24-, 32-, and 64-core server and embedded processors.
**
Radeon
Radeon () is a brand of computer products, including graphics processing units, random-access memory, RAM disk software, and solid-state drives, produced by Radeon Technologies Group, a division of AMD. The brand was launched in 2000 by ATI Tech ...
and
FireStream GPU
A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobi ...
/
GPGPU
General-purpose computing on graphics processing units (GPGPU, or less often GPGP) is the use of a graphics processing unit (GPU), which typically handles computation only for computer graphics, to perform computation in applications traditiona ...
.
*
Analog Devices
Analog Devices, Inc. (ADI), also known simply as Analog, is an American multinational semiconductor company specializing in data conversion, signal processing and power management technology, headquartered in Wilmington, Massachusetts.
The co ...
Blackfin BF561, a symmetrical dual-core processor
*
ARM
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...
MPCore is a fully synthesizable multi-core container for
ARM11 MPCore
ARM11 is a group of 32-bit RISC ARM processor cores licensed by ARM Holdings. The ARM11 core family consists of ARM1136J(F)-S, ARM1156T2(F)-S, ARM1176JZ(F)-S, and ARM11MPCore. Since ARM11 cores were released from 2002 to 2005, they are no lon ...
and
ARM Cortex-A9 MPCore
The ARM Cortex-A9 MPCore is a 32-bit multi-core processor that provides up to 4 cache-coherent cores, each implementing the ARM v7 architecture instruction set. It was introduced in 2007.
Features
Key features of the Cortex-A9 core are:
* ...
processor cores, intended for high-performance embedded and entertainment applications.
*
ASOCS
ASOCS Ltd. is a privately held company,a developer of on-premise cloud solutions for industries such as retail, real estate, hospitality, health, sports and entertainment. ASOCS is also collaborating with mobile network carriers to support the mo ...
ModemX, up to 128 cores, wireless applications.
*
Azul Systems
Azul Systems, Inc. develops runtimes ( JDKs, JVMs) for executing Java-based applications. Founded in March 2002, Azul Systems is headquartered in Sunnyvale, California
Products Azul Platform Prime (Formerly Zing)
Azul produces ''Platform ...
** Vega 1, a 24-core processor, released in 2005.
** Vega 2, a 48-core processor, released in 2006.
** Vega 3, a 54-core processor, released in 2008.
* Broadcom SiByte SB1250, SB1255, SB1455; BCM 2836 quad-core ARM SoC (designed for the
Raspberry Pi
Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic ...
2)
*
Cadence Design Systems
Cadence Design Systems, Inc. (stylized as cādence), headquartered in San Jose, California, is an American multinational corporation, multinational computational software company, founded in 1988 by the merger of SDA Systems and ECAD, Inc. The co ...
Tensilica
Tensilica was a company based in Silicon Valley in the semiconductor intellectual property core business. It is now a part of Cadence Design Systems.
Tensilica is known for its customizable Xtensa microprocessor core. Other products include: HiF ...
Xtensa LX6, available in a dual-core configuration in
Espressif Systems's
ESP32
ESP32 is a series of low-cost, low-power system on a chip microcontrollers with integrated Wi-Fi and dual-mode Bluetooth. The ESP32 series employs either a Tensilica Xtensa LX6 microprocessor in both dual-core and single-core variations, Xtensa L ...
*
ClearSpeed
ClearSpeed Technology Ltd was a semiconductor company, formed in 2002 to develop enhanced SIMD processors for use in high-performance computing and embedded systems. Based in Bristol, UK, the company has been selling its processors since 2005. ...
** CSX700, 192-core processor, released in 2008 (32/64-bit floating point; Integer ALU).
* Cradle Technologies CT3400 and CT3600, both multi-core DSPs.
*
Cavium Networks
Cavium was a fabless semiconductor company based in San Jose, California, specializing in ARM-based and MIPS-based network, video and security processors and SoCs. The company was co-founded in 2000 by Syed B. Ali and M. Raghib Hussain, who wer ...
Octeon, a 32-core
MIPS MPU.
Coherent Logixhx3100 Processor
a 100-core DSP/GPP processor.
* Freescale Semiconductor
Freescale Semiconductor, Inc. was an American semiconductor manufacturer. It was created by the divestiture of the Semiconductor Products Sector of Motorola in 2004. Freescale focused their integrated circuit products on the automotive, embed ...
QorIQ series processors, up to 8 cores, Power ISA
Power ISA is a reduced instruction set computer (RISC) instruction set architecture (ISA) currently developed by the OpenPOWER Foundation, led by IBM. It was originally developed by IBM and the now-defunct Power.org industry group. Power IS ...
MPU.
* Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...
PA-8800
The PA-8000 (PCX-U), code-named ''Onyx'', is a microprocessor developed and fabricated by Hewlett-Packard (HP) that implemented the PA-RISC 2.0 instruction set architecture (ISA). Hunt 1995 It was a completely new design with no circuitry derived ...
and PA-8900
The PA-8000 (PCX-U), code-named ''Onyx'', is a microprocessor developed and fabricated by Hewlett-Packard (HP) that implemented the PA-RISC 2.0 instruction set architecture (ISA). Hunt 1995 It was a completely new design with no circuitry derived ...
, dual core PA-RISC
PA-RISC is an instruction set architecture (ISA) developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer (RISC) architecture, where the PA stands for Precision Architecture. The design is also referred to as ...
processors.
* IBM
** POWER4
The POWER4 is a microprocessor developed by International Business Machines (IBM) that implemented the 64-bit PowerPC and PowerPC AS instruction set architectures. Released in 2001, the POWER4 succeeded the POWER3 and RS64 microprocessors, ena ...
, a dual-core PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...
processor, released in 2001.
** POWER5, a dual-core PowerPC processor, released in 2004.
** POWER6
The POWER6 is a microprocessor developed by IBM that implemented the Power ISA v.2.03. When it became available in systems in 2007, it succeeded the POWER5+ as IBM's flagship Power microprocessor. It is claimed to be part of the eCLipz projec ...
, a dual-core PowerPC processor, released in 2007.
** POWER7
POWER7 is a family of superscalar multi-core microprocessors based on the Power ISA 2.06 instruction set architecture released in 2010 that succeeded the POWER6 and POWER6+. POWER7 was developed by IBM at several sites including IBM's Roche ...
, a 4,6,8-core PowerPC processor, released in 2010.
** POWER8
POWER8 is a family of superscalar multi-core microprocessors based on the Power ISA, announced in August 2013 at the Hot Chips conference. The designs are available for licensing under the OpenPOWER Foundation, which is the first time for s ...
, a 12-core PowerPC processor, released in 2013.
** POWER9
POWER9 is a family of superscalar, multithreading, multi-core microprocessors produced by IBM, based on the Power ISA. It was announced in August 2016. The POWER9-based processors are being manufactured using a 14 nm FinFET process, in ...
, a 12 or 24-core PowerPC processor, released in 2017.
** Power10
Power10 is a superscalar, multithreading, multi-core microprocessor family, based on the open source Power ISA, and announced in August 2020 at the Hot Chips conference; systems with Power10 CPUs. Generally available from September 2021 in th ...
, a 15 or 30-core PowerPC processor, released in 2021.
** PowerPC 970
The PowerPC 970, PowerPC 970FX, and PowerPC 970MP are 64-bit PowerPC processors from IBM introduced in 2002. When used in PowerPC-based Macintosh computers, Apple referred to them as the PowerPC G5.
The 970 family was created through a collab ...
MP, a dual-core PowerPC processor, used in the Apple Power Mac G5
The Power Mac G5 is a series of personal computers designed, manufactured, and sold by Apple Computer, Inc. from 2003 to 2006 as part of the Power Mac series. When introduced, it was the most powerful computer in Apple's Macintosh lineup, and ...
.
** Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...
, a triple-core, SMT-capable, PowerPC microprocessor used in the Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...
Xbox 360
The Xbox 360 is a home video game console developed by Microsoft. As the successor to the original Xbox, it is the second console in the Xbox series. It competed with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation ...
game console.
** z10, a quad-core z/Architecture
z/Architecture, initially and briefly called ESA Modal Extensions (ESAME), is IBM's 64-bit complex instruction set computer (CISC) instruction set architecture, implemented by its mainframe computers. IBM introduced its first z/Architecture-b ...
processor, released in 2008.
** z196, a quad-core z/Architecture processor, released in 2010.
** zEC12, a six-core z/Architecture processor, released in 2012.
** z13, an eight-core z/Architecture processor, released in 2015.
** z14, a ten-core z/Architecture processor, released in 2017.
** z15, a twelve-core z/Architecture processor, released in 2019.
** Telum, an eight-core z/Architecture processor, released in 2021.
* Infineon
Infineon Technologies AG is a German semiconductor manufacturer founded in 1999, when the semiconductor operations of the former parent company Siemens AG were spun off. Infineon has about 50,280 employees and is one of the ten largest semicond ...
** AURIX
AURIX (Automotive Realtime Integrated Next Generation Architecture) is a 32-bit Infineon microcontroller family, targeting the automotive industry. It is based on multicore architecture of up to three independent 32-bit TriCore CPUs.
Applicati ...
** Danube, a dual-core, MIPS-based, home gateway
A residential gateway is a small consumer-grade gateway which bridges network access between connected local area network (LAN) hosts to a wide area network (WAN) (such as the Internet) via a modem, or directly connects to a WAN (as in EttH), whi ...
processor.
* Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
** Atom
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons.
Every solid, liquid, gas, and ...
, single, dual-core, quad-core, 8-, 12-, and 16-core processors for netbooks
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Inte ...
, nettops, embedded applications, and mobile internet devices
A mobile Internet device (MID) is a multimedia capable mobile device providing wireless Internet access. They are designed to provide entertainment, information and location-based services for personal or business use. They allow 2-way communicati ...
(MIDs).
** Atom SoC (system on a chip), single-core, dual-core, and quad-core processors for smartphones and tablets.
** Celeron
Celeron is Intel's brand name for low-end IA-32 and x86-64 computer microprocessor models targeted at low-cost personal computers.
Celeron processors are compatible with IA-32
IA-32 (short for "Intel Architecture, 32-bit", commonly called ...
, the first dual-core (and, later, quad-core) processor for the budget/entry-level market.
** Core Duo
Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the time ...
, a dual-core processor.
** Core 2 Duo
Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel, Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the ...
, a dual-core processor.
** Core 2 Quad
Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the time o ...
, 2 dual-core dies packaged in a multi-chip module.
** Core i3
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the central ...
, Core i5
The following is a list of Intel Core i5 brand microprocessors. Introduced in 2009, the Core i5 line of microprocessors are intended to be used by mainstream users.
Desktop processors
Nehalem microarchitecture (1st generation)
"Lynnf ...
, Core i7
The following is a list of Intel Core i7 brand microprocessors. Introduced in 2008, the Core i7 line of microprocessors are intended to be used by high-end users.
Desktop processors
Nehalem microarchitecture (1st generation)
"Bloomfield" ...
and Core i9
The following is a list of Intel Core i9 brand microprocessors. They were introduced in May 2017 for LGA 2066 chips, also known as Intel Core X-series processors. With their high number of cores, high power draw, high thermal output, and high pe ...
, a family of dual-, quad-, 6-, 8-, 10-, 12-, 14-, 16-, and 18-core processors, and the successor of the Core 2 Duo
Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel, Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the ...
and the Core 2 Quad
Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the time o ...
.
** Itanium
Itanium ( ) is a discontinued family of 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). Launched in June 2001, Intel marketed the processors for enterprise servers and high-performance computin ...
, single, dual-core, quad-core, and 8-core processors.
** Pentium
Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium processor from which the brand took its name was first released on March 22, 1993. After that, the Pentium II and Pe ...
, single, dual-core, and quad-core processors for the entry-level market.
** Teraflops Research Chip
Intel Teraflops Research Chip (codenamed ''Polaris'') is a research manycore processor containing 80 cores, using a network-on-chip architecture, developed by Intel's Tera-Scale Computing Research Program. It was manufactured using a 65 n ...
(Polaris), a 3.16 GHz, 80-core processor prototype, which the company originally stated would be released by 2011.
** Xeon
Xeon ( ) is a brand of x86 microprocessors designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server, and embedded system markets. It was introduced in June 1998. Xeon processors are based on the same arc ...
dual-, quad-, 6-, 8-, 10-, 12-, 14-, 15-, 16-, 18-, 20-, 22-, 24-, 26-, 28-, 32-, 48-, and 56-core processors.
** Xeon Phi
Xeon Phi was a series of x86 manycore processors designed and made by Intel. It was intended for use in supercomputers, servers, and high-end workstations. Its architecture allowed use of standard programming languages and application program ...
57-, 60-, 61-, 64-, 68-, and 72-core processors.
* IntellaSys
** SEAforth 40C18, a 40-core processor.
** SEAforth24, a 24-core processor designed by Charles H. Moore
Charles Havice Moore II (born 9 September 1938), better known as Chuck Moore, is an American computer engineer and programmer, best known for inventing the Forth programming language in 1968. He cofounded FORTH, Inc., with Elizabeth Rather in ...
.
* Kalray
Kalray is a fabless semiconductor company.
Founded in 2008 as a spin-off of CEA French lab, with investors such as Renault–Nissan–Mitsubishi Alliance, Safran, NXP Semiconductors, CEA and Bpifrance.
Product history
The first Kalray paten ...
** MPPA-256, 256-core processor, released 2012 (256 usable VLIW cores, Network-on-Chip (NoC), 32/64-bit IEEE 754 compliant FPU)
* NetLogic Microsystems
** XLP, a 32-core, quad-threaded MIPS64 processor.
** XLR, an eight-core, quad-threaded MIPS64 processor.
** XLS, an eight-core, quad-threaded MIPS64 processor.
* Nvidia
Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as VIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as VIDIA with a large italicized lowercase "n" on products from the mid 1990s to ...
** RTX 3090 (10496 CUDA cores, GPGPU
General-purpose computing on graphics processing units (GPGPU, or less often GPGP) is the use of a graphics processing unit (GPU), which typically handles computation only for computer graphics, to perform computation in applications traditiona ...
cores; plus other more specialized cores).
* Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
Propeller P8X32, an eight-core microcontroller.
* picoChip PC200 series 200–300 cores per device for DSP & wireless.
* Plurality HAL series tightly coupled 16-256 cores, L1 shared memory, hardware synchronized processor.
* Rapport Kilocore KC256, a 257-core microcontroller with a PowerPC core and 256 8-bit "processing elements".
* SiCortex SiCortex was a supercomputer manufacturer founded in 2003 and headquartered in Clock Tower Place,
Maynard, Massachusetts. On 27 May 2009, ''HPCwire'' reported that the company had shut down its operations, laid off most of its staff, and is seekin ...
"SiCortex node" has six MIPS64 cores on a single chip.
* SiFive
** U74 includes 4 cores
* Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
/ IBM/Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure system ...
's Cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
processor, a nine-core processor with one general purpose PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...
core and eight specialized SPUs (Synergistic Processing Unit) optimized for vector operations used in the Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
PlayStation 3
The PlayStation 3 (PS3) is a home video game console developed by Sony Interactive Entertainment, Sony Computer Entertainment. The successor to the PlayStation 2, it is part of the PlayStation brand of consoles. It was first released on Novemb ...
.
* Sun Microsystems
Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...
** MAJC
MAJC (Microprocessor Architecture for Java Computing) was a Sun Microsystems multi-core, multithreaded, very long instruction word (VLIW) microprocessor design from the mid-to-late 1990s. Originally called the UltraJava processor, the MAJC proces ...
5200, two-core VLIW processor.
** UltraSPARC IV
The UltraSPARC IV ''Jaguar'' and follow-up UltraSPARC IV+ ''Panther'' are microprocessors designed by Sun Microsystems and manufactured by Texas Instruments. They are the fourth generation of UltraSPARC microprocessors, and implement the 64-bit S ...
and UltraSPARC IV+, dual-core processors.
** UltraSPARC T1
Sun Microsystems' UltraSPARC T1 microprocessor, known until its 14 November 2005 announcement by its development codename "Niagara", is a multithreading, multicore CPU. Designed to lower the energy consumption of server computers, the CPU ty ...
, an eight-core, 32-thread processor.
** UltraSPARC T2
Sun Microsystems' UltraSPARC T2 microprocessor is a multithreading, multi-core CPU. It is a member of the SPARC family, and the successor to the UltraSPARC T1. The chip is sometimes referred to by its codename, Niagara 2. Sun started selling ...
, an eight-core, 64-concurrent-thread processor.
** UltraSPARC T3, a sixteen-core, 128-concurrent-thread processor.
** SPARC T4
The SPARC T4 is a SPARC multicore microprocessor introduced in 2011 by Oracle Corporation. The processor is designed to offer high multithreaded performance (8 threads per core, with 8 cores per chip), as well as high single threaded performan ...
, an eight-core, 64-concurrent-thread processor.
** SPARC T5
SPARC T5 is the fifth generation multicore microprocessor of Oracle's SPARC T series family. It was first presented at Hot Chips 24 in August 2012, and was officially introduced with the Oracle SPARC T5 servers in March 2013. The processor is ...
, a sixteen-core, 128-concurrent-thread processor.
* Sunway
** Sunway SW26010 The SW26010 is a 260-core manycore processor designed by the Shanghai Integrated Circuit Technology and Industry Promotion Center (ICC for short)( Chinese: 上海集成电路技术与产业促进中心 (简称ICC)). It implements the Sunway architec ...
, a 260-core processor used in the Sunway TaihuLight.
* Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...
** TMS320C80 MVP, a five-core multimedia video processor.
** TMS320TMS320C66, 2,4,8 core DSP.
* Tilera
Tilera Corporation was a fabless semiconductor company focusing on manycore embedded processor design. The company shipped multiple processors, including the TILE64, TILE''Pro''64, and the TILE''Pro''36, TILE-Gx72, TILE-Gx36, TILE-Gx16 and TILE- ...
** TILE64
TILE64 is a VLIW ISA multicore processor manufactured by Tilera. It consists of a mesh network of 64 "tiles", where each tile houses a general purpose processor, cache, and a non-blocking router, which the tile uses to communicate with the o ...
, a 64-core 32-bit processor.
** TILE-Gx
TILE-Gx is a VLIW ISA multicore processor family by Tilera. It consists of a mesh network of up to 100 cores. It is to be produced by TSMC
Taiwan Semiconductor Manufacturing Company Limited (TSMC; also called Taiwan Semiconductor) is a Tai ...
, a 72-core 64-bit processor.
* XMOS
XMOS is a fabless semiconductor company that develops audio products and multicore microcontrollers.
Company history
XMOS was founded in July 2005 by Ali Dixon, James Foster, Noel Hurley, David May, and Hitesh Mehta. It received seed funding ...
Software Defined Silicon
XMOS is a fabless semiconductor company that develops audio products and multicore microcontrollers.
Company history
XMOS was founded in July 2005 by Ali Dixon, James Foster, Noel Hurley, David May, and Hitesh Mehta. It received seed funding ...
quad-core XS1-G4.
Free
*
OpenSPARC OpenSPARC is an open-source hardware project started in December 2005. The initial contribution to the project was Sun Microsystems' register-transfer level (RTL) Verilog code for a full 64-bit, 32- thread microprocessor, the UltraSPARC T1 process ...
Academic
*
MIT
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...
, 16-cor
RAWprocessor
*
University of California, Davis
The University of California, Davis (UC Davis, UCD, or Davis) is a public land-grant research university near Davis, California. Named a Public Ivy, it is the northernmost of the ten campuses of the University of California system. The institut ...
,
Asynchronous array of simple processors
Asynchrony is the state of not being in synchronization.
Asynchrony or asynchronous may refer to:
Electronics and computing
* Asynchrony (computer programming), the occurrence of events independent of the main program flow, and ways to deal with ...
(AsAP)
** 36-core 610 MHz
AsAP
** 167-core 1.2 GHz
AsAP2
*
University of Washington
The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington.
Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle a ...
Wavescalarprocessor
*
University of Texas, Austin
The University of Texas at Austin (UT Austin, UT, or Texas) is a public research university in Austin, Texas. It was founded in 1883 and is the oldest institution in the University of Texas System. With 40,916 undergraduate students, 11,075 ...
,
TRIPS
The Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) is an international legal agreement between all the member nations of the World Trade Organization (WTO). It establishes minimum standards for the regulation by nat ...
processor
*
Linköping University
Linköping University (, LiU) is a public research university based in Linköping, Sweden. Originally established in 1969, it was granted full university status in 1975 and is one of Sweden's largest academic institutions. The university has fou ...
, Sweden, ePUMA processor
*
UC Davis
The University of California, Davis (UC Davis, UCD, or Davis) is a public land-grant research university near Davis, California. Named a Public Ivy, it is the northernmost of the ten campuses of the University of California system. The institut ...
,
Kilocore, a 1000 core 1.78 GHz processor on a 32 nm IBM process
Benchmarks
The research and development of multicore processors often compares many options, and benchmarks are developed to help such evaluations. Existing benchmarks include SPLASH-2, PARSEC, and COSMIC for heterogeneous systems.
See also
*
CPU shielding
*
CUDA
CUDA (or Compute Unified Device Architecture) is a parallel computing platform and application programming interface (API) that allows software to use certain types of graphics processing units (GPUs) for general purpose processing, an approach ca ...
*
GPGPU
General-purpose computing on graphics processing units (GPGPU, or less often GPGP) is the use of a graphics processing unit (GPU), which typically handles computation only for computer graphics, to perform computation in applications traditiona ...
*
Hyper-threading
Hyper-threading (officially called Hyper-Threading Technology or HT Technology and abbreviated as HTT or HT) is Intel's proprietary simultaneous multithreading (SMT) implementation used to improve parallelization of computations (doing multip ...
*
Manycore
Manycore processors are special kinds of multi-core processors designed for a high degree of parallel processing, containing numerous simpler, independent processor cores (from a few tens of cores to thousands or more). Manycore processors are use ...
*
Multicore Association
The Multicore Association was founded in 2005. Multicore Association is a member-funded, non-profit, industry consortium focused on the creation of open standard APIs, specifications, and guidelines that allow system developers and programmers to ...
*
Multitasking
*
OpenCL
OpenCL (Open Computing Language) is a framework for writing programs that execute across heterogeneous platforms consisting of central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), field-progra ...
(Open Computing Language) – a framework for heterogeneous execution
*
Parallel random access machine
In computer science, a parallel random-access machine (parallel RAM or PRAM) is a shared memory architecture, shared-memory abstract machine. As its name indicates, the PRAM is intended as the parallel-computing analogy to the random-access machin ...
*
Partitioned global address space
In computer science, partitioned global address space (PGAS) is a parallel programming model paradigm. PGAS is typified by communication operations involving a global memory address space abstraction that is logically partitioned, where a portion ...
(PGAS)
*
Race condition
A race condition or race hazard is the condition of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events. It becomes a bug when one or more of t ...
*
Thread
Notes
#
Digital signal processor
A digital signal processor (DSP) is a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing. DSPs are fabricated on MOS integrated circuit chips. They are widely used in audio si ...
s (DSPs) have used multi-core architectures for much longer than high-end general-purpose processors. A typical example of a DSP-specific implementation would be a combination of a
RISC
In computer engineering, a reduced instruction set computer (RISC) is a computer designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set comput ...
CPU and a DSP
MPU. This allows for the design of products that require a general-purpose processor for user interfaces and a DSP for real-time data processing; this type of design is common in
mobile phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...
s. In other applications, a growing number of companies have developed multi-core DSPs with very large numbers of processors.
# Two types of
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
s are able to use a dual-CPU multiprocessor: partitioned multiprocessing and
symmetric multiprocessing
Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ...
(SMP). In a partitioned architecture, each CPU boots into separate segments of physical memory and operate independently; in an SMP OS, processors work in a shared space, executing threads within the OS independently.
References
Further reading
*
*
External links
"What Is a Processor Core?"MakeUseOf
"Embedded moves to multicore"''Embedded Computing Design''
"Multicore Is Bad News for Supercomputers"''
IEEE Spectrum
''IEEE Spectrum'' is a magazine edited by the Institute of Electrical and Electronics Engineers.
The first issue of ''IEEE Spectrum'' was published in January 1964 as a successor to ''Electrical Engineering''. The magazine contains peer-revie ...
''
Architecting solutions for the Manycore future published on Feb 19, 2010 (more than one dead link in the slide)
{{Authority control
Computer architecture
Digital signal processing
Flynn's taxonomy
Microprocessors
Parallel computing