Symmetric multiprocessing
Encyclopedia
In computing
, symmetric multiprocessing (SMP) involves a multiprocessor
computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture. In the case of multi-core
processors, the SMP architecture applies to the cores, treating them as separate processors. Processors may be interconnected using buses, crossbar switch
es or on-chip mesh networks. The bottleneck in the scalability of SMP using buses or crossbar switches is the bandwidth and power consumption of the interconnect among the various processors, the memory, and the disk arrays. Mesh architectures avoid these bottlenecks, and provide nearly linear scalability to much higher processor counts at the sacrifice of programmability:
A computer system that uses symmetric multiprocessing is called a symmetric multiprocessor or symmetric multiprocessor system
(SMP system). SMP systems allow any processor to work on any task no matter where the data for that task are located in memory, provided that each task in the system is not in execution on two or more processors at the same time; with proper operating system
support, SMP systems can easily move tasks between processors to balance the workload efficiently.
SMP using a single shared system bus
represents one of the earliest styles of multiprocessor machine architectures, typically used for building smaller computers with up to 8 processors.
Larger computer systems might use newer architectures such as NUMA
(Non-Uniform Memory Access), which dedicates different memory banks to different processors. In a NUMA architecture, processors may access local memory quickly and remote memory more slowly. This can dramatically improve memory throughput as long as the data are localized to specific processes (and thus processors). On the downside, NUMA makes the cost of moving data from one processor to another, as in workload balancing, more expensive. The benefits of NUMA are limited to particular workloads, notably on server
s where the data are often associated strongly with certain tasks or users.
Finally, there is computer clustered multiprocessing (such as Beowulf
), in which not all memory is available to all processors. Clustering techniques are used fairly extensively to build very large supercomputers.
In this discussion, a single processor is denoted as a uni processor (UP).
(multitasked) processing. However, most consumer products such as word processor
s and computer games
are written in such a manner that they cannot gain large benefits from concurrent systems. For games this is usually because writing a program to increase performance on SMP systems can produce a performance loss on uniprocessor
systems. , however, multi-core chips are becoming more common in new computers, and the balance between installed uni- and multi-core computers may change in the coming years.
Uniprocessor and SMP systems require different programming methods to achieve maximum performance. Therefore two separate versions of the same program may have to be maintained, one for each. Programs running on SMP systems may experience a performance increase even when they have been written for uniprocessor systems. This is because hardware interrupts that usually suspend program execution while the kernel handles them can execute on an idle processor instead. The effect in most applications (e.g. games) is not so much a performance increase as the appearance that the program is running much more smoothly. In some applications, particularly compiler
s and some distributed computing
projects, one will see an improvement by a factor of (nearly) the number of additional processors.
In situations where more than one program executes at the same time, an SMP system will have considerably better performance than a uni-processor because different programs can run on different CPUs simultaneously.
Systems programmers must build support for SMP into the operating system
: otherwise, the additional processors remain idle and the system functions as a uniprocessor system.
In cases where an SMP environment processes many jobs, administrators often experience a loss of hardware efficiency. Software programs have been developed to schedule jobs so that the processor utilization reaches its maximum potential. Good software packages can achieve this maximum potential by scheduling each CPU separately, as well as being able to integrate multiple SMP machines and clusters.
Access to RAM is serialized; this and cache coherency
issues causes performance to lag slightly behind the number of additional processors in the system (aga).
s and workstations with two processors dominated the SMP market. With the introduction of dual-core devices
, SMP is found in most new desktop machines and in many laptop machines. The most popular entry-level SMP systems use the x86 instruction set
architecture and are based on Intel’s Xeon
, Pentium D
, Core Duo, and Core 2 Duo
based processors or AMD’s Athlon64 X2, Quad FX or Opteron
200 and 2000 series processors. Servers use those processors and other readily available non-x86 processor choices, including the Sun Microsystems
UltraSPARC
, Fujitsu
SPARC64 III and later, SGI
MIPS
, Intel Itanium
, Hewlett Packard PA-RISC
, Hewlett-Packard (merged with Compaq
which acquired first Digital Equipment Corporation
) DEC Alpha
, IBM POWER
and Apple Computer
PowerPC
(specifically G4 and G5 series, as well as earlier PowerPC 604 and 604e series) processors. In all cases, these systems are available in uniprocessor versions as well.
Earlier SMP systems used motherboards that have two or more CPU sockets. , microprocessor manufacturers introduced CPU devices with two or more processors in one device, for example, the Itanium
, POWER
, UltraSPARC
, Opteron
, Athlon
, Core 2, and Xeon
all have multi-core variants. Athlon and Core 2 Duo multiprocessors are socket-compatible with uniprocessor variants, so an expensive dual socket motherboard is no longer needed to implement an entry-level SMP machine. It should also be noted that dual socket Opteron
designs are technically ccNUMA designs, though they can be programmed as SMP for a slight loss in performance.
It was implemented later on other mainframes. Mid-level servers, using between four and eight processors, can be found using the Intel Xeon
MP, AMD Opteron
800 and 8000 series and the above-mentioned UltraSPARC, SPARC64, MIPS, Itanium, PA-RISC, Alpha and POWER processors. High-end systems, with sixteen or more processors, are also available with all of the above processors.
Sequent Computer Systems
built large SMP machines using Intel 80386 (and later 80486) processors. Some smaller 80486 systems existed, but the major x86 SMP market began with the Intel Pentium technology supporting up to two processors. The Intel Pentium Pro
expanded SMP support with up to four processors natively. Later, the Intel Pentium II
, and Intel Pentium III
processors allowed dual CPU systems, except for the respective Celeron
s. This was followed by the Intel Pentium II Xeon and Intel Pentium III Xeon processors which could be used with up to four processors in a system natively. In 2001 AMD released their Athlon MP, or MultiProcessor CPU, together with the 760MP motherboard chipset as their first offering in the dual processor marketplace. Although several much larger systems were built, they were all limited by the physical memory addressing limitation of 64 GiB
. With the introduction of 64-bit memory addressing on the AMD64 Opteron
in 2003 and Intel 64 (EM64T) Xeon
in 2005, systems are able to address much larger amounts of memory; their addressable limitation of 16 EiB
is not expected to be reached in the foreseeable future.
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, symmetric multiprocessing (SMP) involves a multiprocessor
Multiprocessor
Computer system having two or more processing units each sharing main memory and peripherals, in order to simultaneously process programs.Sometimes the term Multiprocessor is confused with the term Multiprocessing....
computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture. In the case of multi-core
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
processors, the SMP architecture applies to the cores, treating them as separate processors. Processors may be interconnected using buses, crossbar switch
Crossbar switch
In electronics, a crossbar switch is a switch connecting multiple inputs to multiple outputs in a matrix manner....
es or on-chip mesh networks. The bottleneck in the scalability of SMP using buses or crossbar switches is the bandwidth and power consumption of the interconnect among the various processors, the memory, and the disk arrays. Mesh architectures avoid these bottlenecks, and provide nearly linear scalability to much higher processor counts at the sacrifice of programmability:
Serious programming challenges remain with this kind of architecture because it requires two distinct modes of programming, one for the CPUs themselves and one for the interconnect between the CPUs. A single programming language would have to be able to not only partition the workload, but also comprehend the memory locality, which is severe in a mesh-based architecture.
A computer system that uses symmetric multiprocessing is called a symmetric multiprocessor or symmetric multiprocessor system
SMP - Symmetric Multiprocessor System
Multiprocessor system with centralized Shared-Memory called Main Memory operating under a single OS with two or more homogeneous processors....
(SMP system). SMP systems allow any processor to work on any task no matter where the data for that task are located in memory, provided that each task in the system is not in execution on two or more processors at the same time; with proper operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
support, SMP systems can easily move tasks between processors to balance the workload efficiently.
Alternatives
System bus
A system bus is a single computer bus that connects the major components of a computer system. The technique was developed to reduce costs and improve modularity....
represents one of the earliest styles of multiprocessor machine architectures, typically used for building smaller computers with up to 8 processors.
Larger computer systems might use newer architectures such as NUMA
Non-Uniform Memory Access
Non-Uniform Memory Access is a computer memory design used in Multiprocessing, where the memory access time depends on the memory location relative to a processor...
(Non-Uniform Memory Access), which dedicates different memory banks to different processors. In a NUMA architecture, processors may access local memory quickly and remote memory more slowly. This can dramatically improve memory throughput as long as the data are localized to specific processes (and thus processors). On the downside, NUMA makes the cost of moving data from one processor to another, as in workload balancing, more expensive. The benefits of NUMA are limited to particular workloads, notably on server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
s where the data are often associated strongly with certain tasks or users.
Finally, there is computer clustered multiprocessing (such as Beowulf
Beowulf (computing)
A Beowulf cluster is a computer cluster of what are normally identical, commodity-grade computers networked into a small local area network with libraries and programs installed which allow processing to be shared among them...
), in which not all memory is available to all processors. Clustering techniques are used fairly extensively to build very large supercomputers.
In this discussion, a single processor is denoted as a uni processor (UP).
Advantages and disadvantages
SMP has many uses in science, industry, and business which often use custom-programmed software for multithreadedThread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
(multitasked) processing. However, most consumer products such as word processor
Word processor
A word processor is a computer application used for the production of any sort of printable material....
s and computer games
Computer Games
"Computer Games" is a single by New Zealand group, Mi-Sex released in 1979 in Australia and New Zealand and in 1981 throughout Europe. It was the single that launched the band, and was hugely popular, particularly in Australia and New Zealand...
are written in such a manner that they cannot gain large benefits from concurrent systems. For games this is usually because writing a program to increase performance on SMP systems can produce a performance loss on uniprocessor
Uniprocessor
A uniprocessor system is a computer system with a single central processing unit. As more and more computers employ multiprocessing architectures, such as SMP and MPP, the term is used to refer to systems that still have only one CPU. Most desktop computers are now shipped with multiprocessing...
systems. , however, multi-core chips are becoming more common in new computers, and the balance between installed uni- and multi-core computers may change in the coming years.
Uniprocessor and SMP systems require different programming methods to achieve maximum performance. Therefore two separate versions of the same program may have to be maintained, one for each. Programs running on SMP systems may experience a performance increase even when they have been written for uniprocessor systems. This is because hardware interrupts that usually suspend program execution while the kernel handles them can execute on an idle processor instead. The effect in most applications (e.g. games) is not so much a performance increase as the appearance that the program is running much more smoothly. In some applications, particularly compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...
s and some distributed computing
Distributed computing
Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...
projects, one will see an improvement by a factor of (nearly) the number of additional processors.
In situations where more than one program executes at the same time, an SMP system will have considerably better performance than a uni-processor because different programs can run on different CPUs simultaneously.
Systems programmers must build support for SMP into the operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
: otherwise, the additional processors remain idle and the system functions as a uniprocessor system.
In cases where an SMP environment processes many jobs, administrators often experience a loss of hardware efficiency. Software programs have been developed to schedule jobs so that the processor utilization reaches its maximum potential. Good software packages can achieve this maximum potential by scheduling each CPU separately, as well as being able to integrate multiple SMP machines and clusters.
Access to RAM is serialized; this and cache coherency
Cache coherency
In computing, cache coherence refers to the consistency of data stored in local caches of a shared resource.When clients in a system maintain caches of a common memory resource, problems may arise with inconsistent data. This is particularly true of CPUs in a multiprocessing system...
issues causes performance to lag slightly behind the number of additional processors in the system (aga).
Entry-level systems
Before about 2006, entry-level serverServer (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
s and workstations with two processors dominated the SMP market. With the introduction of dual-core devices
Multi-core (computing)
A multi-core processor is a single computing component with two or more independent actual processors , which are the units that read and execute program instructions...
, SMP is found in most new desktop machines and in many laptop machines. The most popular entry-level SMP systems use the x86 instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
architecture and are based on Intel’s Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
, Pentium D
Pentium D
The Pentium D brand refers to two series of desktop dual-core 64-bit x86-64 microprocessors with the NetBurst microarchitecture manufactured by Intel. Each CPU comprised two dies, each containing a single core, residing next to each other on a multi-chip module package. The brand's first processor,...
, Core Duo, and Core 2 Duo
Intel Core 2
Core 2 is a brand encompassing a range of Intel's consumer 64-bit x86-64 single-, dual-, and quad-core microprocessors based on the Core microarchitecture. The single- and dual-core models are single-die, whereas the quad-core models comprise two dies, each containing two cores, packaged in a...
based processors or AMD’s Athlon64 X2, Quad FX or Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
200 and 2000 series processors. Servers use those processors and other readily available non-x86 processor choices, including the Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
UltraSPARC
UltraSPARC
The UltraSPARC is a microprocessor developed by Sun Microsystems who is now a part of Oracle Corporation and fabricated by Texas Instruments that implements the SPARC V9 instruction set architecture . It was introduced in mid-1995. It was the first microprocessor from Sun Microsystems to implement...
, Fujitsu
Fujitsu
is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
SPARC64 III and later, SGI
Silicon Graphics
Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
, Intel Itanium
Itanium
Itanium is a family of 64-bit Intel microprocessors that implement the Intel Itanium architecture . Intel markets the processors for enterprise servers and high-performance computing systems...
, Hewlett Packard PA-RISC
PA-RISC
PA-RISC is an instruction set architecture developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer architecture, where the PA stands for Precision Architecture...
, Hewlett-Packard (merged with Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
which acquired first Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
) DEC Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
, IBM POWER
IBM POWER
POWER is a reduced instruction set computer instruction set architecture developed by IBM. The name is an acronym for Performance Optimization With Enhanced RISC....
and Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
(specifically G4 and G5 series, as well as earlier PowerPC 604 and 604e series) processors. In all cases, these systems are available in uniprocessor versions as well.
Earlier SMP systems used motherboards that have two or more CPU sockets. , microprocessor manufacturers introduced CPU devices with two or more processors in one device, for example, the Itanium
Itanium
Itanium is a family of 64-bit Intel microprocessors that implement the Intel Itanium architecture . Intel markets the processors for enterprise servers and high-performance computing systems...
, POWER
IBM POWER
POWER is a reduced instruction set computer instruction set architecture developed by IBM. The name is an acronym for Performance Optimization With Enhanced RISC....
, UltraSPARC
UltraSPARC
The UltraSPARC is a microprocessor developed by Sun Microsystems who is now a part of Oracle Corporation and fabricated by Texas Instruments that implements the SPARC V9 instruction set architecture . It was introduced in mid-1995. It was the first microprocessor from Sun Microsystems to implement...
, Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
, Athlon
Athlon
Athlon is the brand name applied to a series of x86-compatible microprocessors designed and manufactured by Advanced Micro Devices . The original Athlon was the first seventh-generation x86 processor and, in a first, retained the initial performance lead it had over Intel's competing processors...
, Core 2, and Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
all have multi-core variants. Athlon and Core 2 Duo multiprocessors are socket-compatible with uniprocessor variants, so an expensive dual socket motherboard is no longer needed to implement an entry-level SMP machine. It should also be noted that dual socket Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
designs are technically ccNUMA designs, though they can be programmed as SMP for a slight loss in performance.
Mid-level systems
The Burroughs D825 first implemented SMP in 1962.It was implemented later on other mainframes. Mid-level servers, using between four and eight processors, can be found using the Intel Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
MP, AMD Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
800 and 8000 series and the above-mentioned UltraSPARC, SPARC64, MIPS, Itanium, PA-RISC, Alpha and POWER processors. High-end systems, with sixteen or more processors, are also available with all of the above processors.
Sequent Computer Systems
Sequent Computer Systems
Sequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
built large SMP machines using Intel 80386 (and later 80486) processors. Some smaller 80486 systems existed, but the major x86 SMP market began with the Intel Pentium technology supporting up to two processors. The Intel Pentium Pro
Pentium Pro
The Pentium Pro is a sixth-generation x86 microprocessor developed and manufactured by Intel introduced in November 1, 1995 . It introduced the P6 microarchitecture and was originally intended to replace the original Pentium in a full range of applications...
expanded SMP support with up to four processors natively. Later, the Intel Pentium II
Pentium II
The Pentium II brand refers to Intel's sixth-generation microarchitecture and x86-compatible microprocessors introduced on May 7, 1997. Containing 7.5 million transistors, the Pentium II featured an improved version of the first P6-generation core of the Pentium Pro, which contained 5.5 million...
, and Intel Pentium III
Pentium III
The Pentium III brand refers to Intel's 32-bit x86 desktop and mobile microprocessors based on the sixth-generation P6 microarchitecture introduced on February 26, 1999. The brand's initial processors were very similar to the earlier Pentium II-branded microprocessors...
processors allowed dual CPU systems, except for the respective Celeron
Celeron
Celeron is a brand name given by Intel Corp. to a number of different x86 computer microprocessor models targeted at budget personal computers....
s. This was followed by the Intel Pentium II Xeon and Intel Pentium III Xeon processors which could be used with up to four processors in a system natively. In 2001 AMD released their Athlon MP, or MultiProcessor CPU, together with the 760MP motherboard chipset as their first offering in the dual processor marketplace. Although several much larger systems were built, they were all limited by the physical memory addressing limitation of 64 GiB
Gib
Gib may refer to:* A castrated male cat or ferret* Gibibit , measurement unit of digitally stored computer information* Gibraltar, British overseas territory* Drywall, construction material...
. With the introduction of 64-bit memory addressing on the AMD64 Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
in 2003 and Intel 64 (EM64T) Xeon
Xeon
The Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
in 2005, systems are able to address much larger amounts of memory; their addressable limitation of 16 EiB
Exabyte
The exabyte is a unit of information or computer storage equal to one quintillion bytes . The unit symbol for the exabyte is EB...
is not expected to be reached in the foreseeable future.
Operating systems running on SMP computers
- BeOSBeOSBeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
and derivatives - BSD descendants:
- DragonFly BSDDragonFly BSDDragonFly BSD is a free Unix-like operating system created as a fork of FreeBSD 4.8. Matthew Dillon, an Amiga developer in the late 1980s and early 1990s and a FreeBSD developer between 1994 and 2003, began work on DragonFly BSD in June 2003 and announced it on the FreeBSD mailing lists on July...
- FreeBSDFreeBSDFreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
- NetBSDNetBSDNetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
- OpenBSDOpenBSDOpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...
- DragonFly BSD
- Burroughs (Unisys) MCPMCP (Burroughs Large Systems)The MCP is the proprietary operating system of the Burroughs large systems including the Unisys Clearpath/MCP systems....
(1961–present) - HP-UXHP-UXHP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
- IBM AIX
- IBM i (formerly known as i5/OS or OS/400)
- INTEGRITYIntegrity (operating system)INTEGRITY is a real-time operating system produced and marketed by Green Hills Software. It is royalty-free, POSIX-certified, and intended for use in embedded systems needing reliability, availability, and fault tolerance. It is built atop the velOSity microkernel and is intended mainly for modern...
- IRIXIRIXIRIX is a computer operating system developed by Silicon Graphics, Inc. to run natively on their 32- and 64-bit MIPS architecture workstations and servers. It was based on UNIX System V with BSD extensions. IRIX was the first operating system to include the XFS file system.The last major version...
- LynxOSLynxOSThe LynxOS RTOS is a Unix-like real-time operating system from LynuxWorks . Sometimes known as the Lynx Operating System, LynxOS features full POSIX conformance and, more recently, Linux compatibility...
- LabVIEW Real-Time Module (version 8.5 or later)
- LinuxLinux kernelThe Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
-based systems - Mac OSMac OSMac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
(7.5.5 to 9.2.2) and Mac OS XMac OS XMac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems... - The Microsoft Windows NT family (this includes Windows 2000Windows 2000Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15 December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the...
, Windows XPWindows XPWindows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
, Windows VistaWindows VistaWindows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
, Windows 7, Windows Server 2003Windows Server 2003Windows Server 2003 is a server operating system produced by Microsoft, introduced on 24 April 2003. An updated version, Windows Server 2003 R2, was released to manufacturing on 6 December 2005...
, Windows Server 2008, etc.) - Microsoft Windows Embedded Compact (formerly known as Windows Embedded CE / Windows CE.NET / Windows CEWindows CEMicrosoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...
) has added SMP support at version 7 - Nucleus RTOSNucleus RTOSNucleus OS is a real-time operating system and toolset created by the Embedded Systems Division of Mentor Graphics for various central processing unit platforms. Nucleus OS is an embedded software solution and is in an estimated 2.11 billion devices worldwide.Development is typically done on a...
- OpenVMSOpenVMSOpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
(since VMS 5.0) - OS/2OS/2OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal...
(since 2.11) - OSEOperating System EmbeddedThe Operating System Embedded is a real-time embedded operating system created by the Swedish information technology company ENEA AB. Bengt Eliasson, who at the time was a consultant from ENEA with an assignment at Ericsson, wrote the basic parts of the kernel...
real-time operating systemReal-time operating systemA real-time operating system is an operating system intended to serve real-time application requests.A key characteristic of a RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task; the variability is jitter...
(OSE5) - PikeOSPikeOSPikeOS is a microkernel-based real-time operating system made by SYSGO AG. It is targeted at safety and security critical embedded systems. It provides a partitioned environment for multiple operating systems with different design goals, safety requirements, or security requirements to coexist in a...
real-time operating system for embedded systems - Plan 9Plan 9 from Bell LabsPlan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
- QNXQNXQNX is a commercial Unix-like real-time operating system, aimed primarily at the embedded systems market. The product was originally developed by Canadian company, QNX Software Systems, which was later acquired by Canadian BlackBerry-producer Research In Motion.-Description:As a microkernel-based...
real-time operating systemReal-time operating systemA real-time operating system is an operating system intended to serve real-time application requests.A key characteristic of a RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task; the variability is jitter...
(2000–present) - Sequent DYNIXDynixDynix is an operating system developed by Sequent. It is a flavor of Unix based on BSD. DYNIX was replaced by DYNIX/ptx, which was based on the System V version of UNIX produced by AT&T....
and DYNIX/ptx - SkyOSSkyOSSkyOS was a prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. As of January 30, 2009 development has halted and no plans to resume its development have been announced.- History :...
- Sun SolarisSolaris Operating SystemSolaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....
- SyllableSyllable (operating system)Syllable Desktop is a free and open source operating system for Pentium and compatible processors. Its purpose is to create an easy-to-use desktop operating system for the home and small office user...
- Tandem/HP NonStop kernelNonStopNonStop can refer to the line of HP Integrity NonStop computers, the line of Tandem NonStop computers that preceded them, or the NonStop OS operating system that is designed for them. NonStop systems are based on an integrated hardware/software stack...
- TOPS-10TOPS-10The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
Operating System for PDP-10PDP-10The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
36-bit architecture (True SMP since version 7.01) - UNIVACUNIVACUNIVAC is the name of a business unit and division of the Remington Rand company formed by the 1950 purchase of the Eckert-Mauchly Computer Corporation, founded four years earlier by ENIAC inventors J. Presper Eckert and John Mauchly, and the associated line of computers which continues to this day...
EXEC 8EXEC 8EXEC 8 was UNIVAC's operating system developed for the UNIVAC 1108 in 1964. It combined the best features of the earlier operating systems: EXEC I and EXEC II . EXEC 8 was one of the first commercially successful multiprocessing operating systems...
(1964–present) - VxWorksVxWorksVxWorks is a real-time operating system developed as proprietary software by Wind River Systems of Alameda, California, USA. First released in 1987, VxWorks is designed for use in embedded systems.- History :...
- z/OSZ/OSz/OS is a 64-bit operating system for mainframe computers, produced by IBM. It derives from and is the successor to OS/390, which in turn followed a string of MVS versions.Starting with earliest:*OS/VS2 Release 2 through Release 3.8...
- z/TPF
- z/VMZ/VMz/VM is the current version in IBM's VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development . It is directly based on technology and concepts dating back to the 1960s, with IBM's CP/CMS on the IBM System/360-67...
- z/VSE
SMP-capable processors
- ARM
- ARM11 MPCore
- ARM Cortex-A9 MPCoreARM Cortex-A9 MPCoreThe ARM Cortex-A9 MPCore is a 32-bit multicore processor providing up to 4 cache-coherent Cortex-A9 cores, each implementing the ARM v7 instruction set architecture.-Features:Key features of the Cortex-A9 core are:...
- ARM Cortex-A5 MPCore
- ARM Cortex-A15 MPCoreARM Cortex-A15 MPCoreThe ARM Cortex-A15 MPCore is a multicore ARM architecture processor providing an out-of-order superscalar pipeline ARM v7 instruction set running at up to 2.5 GHz. ARM has confirmed that the Cortex A15 core is 40 percent faster than the Cortex-A9 core, all things equal...
- Advanced Micro Devices (AMD)
- Athlon MP
- Athlon 64 X2Athlon 64 X2The Athlon 64 X2 is the first dual-core desktop CPU designed by AMD. It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with another functional core on one die, and connecting both via a shared dual-channel memory controller/north bridge and...
- Turion 64 X2
- AMD Opteron
- PhenomPhenom (processor)Phenom is the 64-bit AMD desktop processor line based on the K10 microarchitecture, in what AMD calls family 10h processors, sometimes incorrectly called "K10h". Triple-core versions belong to the Phenom 8000 series and quad cores to the AMD Phenom X4 9000 series...
- Phenom IIPhenom IIPhenom 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 with DDR3 support, along with an initial batch of...
- Athlon IIAthlon IIAthlon II is a family of AMD multi-core 45 nm central processing units, which is aimed at the midrange to budget market and is a complementary product lineup to the Phenom II.-Features:...
- Azul SystemsAzul SystemsAzul Systems, Inc., a privately held company, develops runtime platforms for executing Java-based applications. Founded in March 2002, Azul Systems is headquartered in Sunnyvale, California, with offices in Slough, United Kingdom; Tokyo, Japan and Bangalore, India.- Products :Azul produces Zing, a...
- Vega 1
- Vega 2
- DEC AlphaDEC AlphaAlpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
- Hewlett-Packard
- HP PA-RISC
- International Business Machines (IBM)
- AIM Apple/IBM/Motorola PowerPC 601, 604, 604ePowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
- IBM POWERIBM POWERPOWER is a reduced instruction set computer instruction set architecture developed by IBM. The name is an acronym for Performance Optimization With Enhanced RISC....
- System z
- AIM Apple/IBM/Motorola PowerPC 601, 604, 604e
- Inmos
- INMOS transputers: T400, T800 and T9000INMOS transputerThe transputer was a pioneering microprocessor architecture of the 1980s, featuring integrated memory and serial communication links, intended for parallel computing. It was designed and produced by Inmos, a British semiconductor company based in Bristol....
- INMOS transputers: T400, T800 and T9000
- Intel
- Intel 486/DX
- Intel OverDrive Processor, Socket 7; Intel OverDrive Processor, Socket 8
- Intel Pentium Pro; Intel Pentium II; Intel Pentium III
- Intel Pentium D
- Intel Core; Intel Pentium Dual-Core; Intel Core 2
- Intel Core i7
- Intel Core i5
- Intel XeonXeonThe Xeon is a brand of multiprocessing- or multi-socket-capable x86 microprocessors from Intel Corporation targeted at the non-consumer server, workstation and embedded system markets.-Overview:...
- Intel Itanium; Intel Itanium 2ItaniumItanium is a family of 64-bit Intel microprocessors that implement the Intel Itanium architecture . Intel markets the processors for enterprise servers and high-performance computing systems...
- glueless up to four processors (max. 16 in IA-32 compatibility mode)
- Motorola/Freescale/Apple
- AIM Apple/IBM/Motorola PowerPC 601, 604, 604ePowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
- AIM Apple/IBM/Motorola PowerPC 601, 604, 604e
- Sun Microsystems
- UltraSPARCSPARCSPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
The Sparkle SPARC Derivative was multi-processor capable in 1991
- UltraSPARC
- SGI/MIPS
- MIPSMIPS architectureMIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
; MIPS64
- MIPS
- Razamicroelectronic
- XLR
- Tilera
- TILE64TILE64TILE64 is a 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 other tiles on the processor....
- 64 cores - TILEPro - 36 and 64 cores
- TILE-Gx - 16, 36, 64 and 100 cores
- TILE64
- Cavium Networks
- Octeon-I, II Up to 32 MIPS64 cores Soc
See also
- Asymmetric Multi-ProcessingAsymmetric multiprocessingAsymmetric multiprocessing, or AMP, was a software stopgap for handling multiple CPUs before symmetric multiprocessing, or SMP, was available.Multiprocessing is the use of more than one CPU in a computer system...
- Massively Parallel ProcessingMassively parallelMassively parallel is a description which appears in computer science, life sciences, medical diagnostics, and other fields.A massively parallel computer is a distributed memory computer system which consists of many individual nodes, each of which is essentially an independent computer in itself,...
- Non-Uniform Memory AccessNon-Uniform Memory AccessNon-Uniform Memory Access is a computer memory design used in Multiprocessing, where the memory access time depends on the memory location relative to a processor...
- Simultaneous multithreadingSimultaneous multithreadingSimultaneous multithreading, often abbreviated as SMT, is a technique for improving the overall efficiency of superscalar CPUs with hardware multithreading...
- Sequent Computer SystemsSequent Computer SystemsSequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
- Software lockoutSoftware lockoutIn multiprocessor computer systems, software lockout is the issue of performance degradation due to the idle wait times spent by the CPUs in kernel-level critical sections. Software lockout is the major cause of scalability degradation in a multiprocessor system, posing a limit on the maximum...
External links
- History of Multi-Processing
- Practical Parallel Programming in Pascal
- Enea OSE
- Linux and Multiprocessing
- Intel
- AMD
- OpenMP - Tutorial for parallel programming
- BMDFM: Binary Modular Dataflow Machine - SMP Runtime Environment (BMDFMBMDFMBMDFM is software, which enables running an application in parallel on shared memory symmetric multiprocessors using the multiple processors to speed up the execution of single applications....
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