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42-598: LARC supported multiprocessing with two CPUs (called Computer s) and an input/output (I/O) Processor (called the Processor ). Two LARC machines were built, the first delivered to Livermore in June 1960, and the second to the Navy's David Taylor Model Basin . Both examples had only one CPU, so no multiprocessor LARCs were ever built. Livermore decommissioned their LARC in December 1968 and

84-927: A multiprocessing system, all CPUs may be equal, or some may be reserved for special purposes. A combination of hardware and operating system software design considerations determine the symmetry (or lack thereof) in a given system. For example, hardware or software considerations may require that only one particular CPU respond to all hardware interrupts, whereas all other work in the system may be distributed equally among CPUs; or execution of kernel-mode code may be restricted to only one particular CPU, whereas user-mode code may be executed in any combination of processors. Multiprocessing systems are often easier to design if such restrictions are imposed, but they tend to be less efficient than systems in which all CPUs are utilized. Systems that treat all CPUs equally are called symmetric multiprocessing (SMP) systems. In systems where all CPUs are not equal, system resources may be divided in

126-411: A multiprocessor is a computer system having two or more processing units (multiple processors) each sharing main memory and peripherals, in order to simultaneously process programs. A 2009 textbook defined multiprocessor system similarly, but noting that the processors may share "some or all of the system’s memory and I/O facilities"; it also gave tightly coupled system as a synonymous term. At

168-423: A time-sharing system ). Multiprocessing however means true parallel execution of multiple processes using more than one processor. Multiprocessing doesn't necessarily mean that a single process or task uses more than one processor simultaneously; the term parallel processing is generally used to denote that scenario. Other authors prefer to refer to the operating system techniques as multiprogramming and reserve

210-466: A high speed communication system ( Gigabit Ethernet is common). A Linux Beowulf cluster is an example of a loosely coupled system. Tightly coupled systems perform better and are physically smaller than loosely coupled systems, but have historically required greater initial investments and may depreciate rapidly; nodes in a loosely coupled system are usually inexpensive commodity computers and can be recycled as independent machines upon retirement from

252-532: A master/slave multiprocessor system of microprocessors is the Tandy/Radio Shack TRS-80 Model 16 desktop computer which came out in February 1982 and ran the multi-user/multi-tasking Xenix operating system, Microsoft's version of UNIX (called TRS-XENIX). The Model 16 has two microprocessors: an 8-bit Zilog Z80 CPU running at 4 MHz, and a 16-bit Motorola 68000 CPU running at 6 MHz. When

294-449: A maximum of 39 banks of core (ten cabinets with one empty bank), 97,500 words. The core memory had one parity bit on each digit for error checking, resulting in 60 bits per memory word. The core memory had an access time of 8 microseconds and a cycle time of 4 microseconds. Each bank operated independently and could begin a new access in any 4-microsecond cycle when it was not already busy. By properly interleaving accesses to different banks

336-646: A multiprocessor with a second Computer . The Processor is an independent CPU (with a different instruction set from the Computer s) and provides control for 12 to 24 magnetic drum storage units, four to forty UNISERVO II tape drives, two electronic page recorders (a 35mm film camera facing a cathode-ray tube), one or two high-speed printers, and a high-speed punched card reader. The LARC used core memory banks of 2500 words each, housed four banks per memory cabinet. The basic configuration had eight banks of core (two cabinets), 20,000 words. The memory could be expanded to

378-403: A new scientific computing system for three-dimensional hydrodynamic calculations. Proposals were requested from IBM and UNIVAC for this new system, to be called Livermore Automatic Reaction Calculator or LARC . According to IBM executive Cuthbert Hurd , such a system would cost roughly $ 2.5 million and would run at one to two MIPS . Delivery was to be two to three years after the contract

420-474: A number of ways, including asymmetric multiprocessing (ASMP), non-uniform memory access (NUMA) multiprocessing, and clustered multiprocessing. In a master/slave multiprocessor system, the master CPU is in control of the computer and the slave CPU(s) performs assigned tasks. The CPUs can be completely different in terms of speed and architecture. Some (or all) of the CPUs can share a common bus, each can also have

462-528: A private bus (for private resources), or they may be isolated except for a common communications pathway. Likewise, the CPUs can share common RAM and/or have private RAM that the other processor(s) cannot access. The roles of master and slave can change from one CPU to another. Two early examples of a mainframe master/slave multiprocessor are the Bull Gamma 60 and the Burroughs B5000 . An early example of

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504-401: A total of 21 kW power. It uses high-speed NPN and PNP germanium drift transistors , with cut-off frequency over 100 MHz, and using ~50 mW each. Some third level circuits use a third voltage level. Each logic level has a delay of about 20 ns. To gain speed in critical areas emitter-follower logic is used to reduce the delay to about 10 ns. It uses the same core memory as

546-519: Is 1.38–1.50 microseconds , multiplication time is 2.48–2.70 microseconds, and division time is 9.00–9.90 microseconds. While the IBM 7030 was not considered successful, it spawned many technologies incorporated in future machines that were highly successful. The Standard Modular System (SMS) transistor logic was the basis for the IBM 7090 line of scientific computers, the IBM 7070 and 7080 business computers,

588-524: The IBM 7040 and IBM 1400 lines, and the IBM 1620 small scientific computer; the 7030 used about 170,000 transistors. The IBM 7302 Model I Core Storage units were also used in the IBM 7090, IBM 7070 and IBM 7080. Multiprogramming , memory protection, generalized interrupts, the eight-bit byte for I/O were all concepts later incorporated in the IBM System/360 line of computers as well as most later central processing units (CPU). Stephen Dunwell,

630-669: The IBM 7090 . The Lawrence Livermore Laboratory's IBM 7030 (except for its core memory ) and portions of the MITRE Corporation/Brigham Young University IBM 7030 now reside in the Computer History Museum collection, in Mountain View, California . Instructions are either 32-bit or 64-bit. The registers overlay the first 32 addresses of memory as shown. The accumulator and index registers operate in sign-and-magnitude format. Main memory

672-471: The IBM System/360 became obvious, he was given an official apology and, in 1966 was made an IBM Fellow . In spite of Stretch's failure to meet its own performance goals, it served as the basis for many of the design features of the successful IBM System/360, which was announced in 1964 and first shipped in 1965. In early 1955, Dr. Edward Teller of the University of California Radiation Laboratory wanted

714-477: The Processor Control Program (written and supplied by UNIVAC with each system), to request needed I/O. The LARC was built using surface-barrier transistors , which were already obsolete by the time the first system was delivered. The LARC was a very fast computer for its time. Its addition time was 4 microseconds, multiplication time was 8 microseconds, and the division time was 28 microseconds. It

756-425: The operating system level, multiprocessing is sometimes used to refer to the execution of multiple concurrent processes in a system, with each process running on a separate CPU or core, as opposed to a single process at any one instant. When used with this definition, multiprocessing is sometimes contrasted with multitasking , which may use just a single processor but switch it in time slices between tasks (i.e.

798-461: The 68000 CPU. The Z-80 can be used to do other tasks. The earlier TRS-80 Model II , which was released in 1979, could also be considered a multiprocessor system as it had both a Z-80 CPU and an Intel 8021 microcontroller in the keyboard. The 8021 made the Model II the first desktop computer system with a separate detachable lightweight keyboard connected with by a single thin flexible wire, and likely

840-449: The 7030 from sales to customers beyond those having already negotiated contracts. PC World magazine named Stretch one of the biggest project management failures in IT history. Within IBM, being eclipsed by the smaller Control Data Corporation seemed hard to accept. The project lead, Stephen W. Dunwell , was initially made a scapegoat for his role in the "failure", but as the success of

882-534: The I/O system the following priorities are enforced: If a higher-priority section is locked out in one 4-microsecond cycle, when it tries again in the next 4-microsecond cycle, all lower-priority sections are prevented from beginning a new cycle on that memory bank until the higher-priority section has completed its access. The LARC's Computers wrote lists of Summary Orders in memory for the Processor to read and interpret by

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924-816: The IBM System/360 Models 91 , 95 and 195 , and the IBM 3090 series as well as computers from other manufacturers. As of 2021 , these techniques are still used in most advanced microprocessors, starting with the 1990s generation that included the Intel Pentium and the Motorola/IBM PowerPC , as well as in many embedded microprocessors and microcontrollers from various manufacturers. The 7030 CPU uses emitter-coupled logic (originally called current-steering logic ) on 18 types of Standard Modular System cards. It uses 4,025 double cards (as shown) and 18,747 single cards, holding 169,100 transistors, requiring

966-1021: The Navy's LARC was turned off in April 1969. The LARC CPUs were able to perform addition in about 4 microseconds, corresponding to about 250 kIPS speed. This made it the fastest computer in the world until 1962 when the IBM 7030 Stretch took the title. The 7030 started as IBM 's entry to the LARC contest, but Teller chose the simpler Univac over the riskier IBM design. The LARC was a decimal mainframe computer with 60 bits per word . It used bi-quinary coded decimal arithmetic with five bits per digit (see below), allowing for 11-digit signed numbers . Instructions were 60 bits long, one per word. The basic configuration had 26 general-purpose registers , which could be expanded to 99. The general-purpose registers had an access time of one microsecond. LARC weighed about 115,000 pounds (58 short tons; 52 t). The basic configuration had one Computer and LARC could be expanded to

1008-656: The Xeon processors via a common pipe and the Opteron processors via independent pathways to the system RAM . Chip multiprocessors, also known as multi-core computing, involves more than one processor placed on a single chip and can be thought of the most extreme form of tightly coupled multiprocessing. Mainframe systems with multiple processors are often tightly coupled. Loosely coupled multiprocessor systems (often referred to as clusters ) are based on multiple standalone relatively low processor count commodity computers interconnected via

1050-411: The ability of a system to support more than one processor or the ability to allocate tasks between them. There are many variations on this basic theme, and the definition of multiprocessing can vary with context, mostly as a function of how CPUs are defined ( multiple cores on one die , multiple dies in one package , multiple packages in one system unit , etc.). According to some on-line dictionaries,

1092-405: The ability to run different operating systems or OS versions on different systems. Merging data from multiple threads or processes may incur significant overhead due to conflict resolution , data consistency , versioning, and synchronization. IBM 7030 Stretch The IBM 7030 , also known as Stretch , was IBM 's first transistorized supercomputer . It was the fastest computer in

1134-511: The bus level. These CPUs may have access to a central shared memory (SMP or UMA ), or may participate in a memory hierarchy with both local and shared memory (SM)( NUMA ). The IBM p690 Regatta is an example of a high end SMP system. Intel Xeon processors dominated the multiprocessor market for business PCs and were the only major x86 option until the release of AMD 's Opteron range of processors in 2004. Both ranges of processors had their own onboard cache but provided access to shared memory;

1176-451: The cluster. Power consumption is also a consideration. Tightly coupled systems tend to be much more energy-efficient than clusters. This is because a considerable reduction in power consumption can be realized by designing components to work together from the beginning in tightly coupled systems, whereas loosely coupled systems use components that were not necessarily intended specifically for use in such systems. Loosely coupled systems have

1218-741: The first keyboard to use a dedicated microcontroller, both attributes that would later be copied years later by Apple and IBM. In multiprocessing, the processors can be used to execute a single sequence of instructions in multiple contexts ( single instruction, multiple data or SIMD, often used in vector processing ), multiple sequences of instructions in a single context ( multiple instruction, single data or MISD, used for redundancy in fail-safe systems and sometimes applied to describe pipelined processors or hyper-threading ), or multiple sequences of instructions in multiple contexts ( multiple instruction, multiple data or MIMD). Tightly coupled multiprocessor systems contain multiple CPUs that are connected at

1260-458: The memory could sustain an effective access time of 4 microseconds on each access (e.g., instruction access in one bank data in another). The data transfer bus connecting the two Computer s and the Processor to the core memory was multiplexed to maximize throughput; every 4- microsecond bus cycle was divided into eight 500-nanosecond time slots: The core memory system enforces a system of interlocks and priorities to avoid simultaneous access of

1302-428: The price of $ 13.5 million was set for the IBM 7030. In 1961, actual benchmarks indicated that the performance of the IBM 7030 was only about 30 times the IBM 704 (i.e. 1.2 MIPS), causing considerable embarrassment for IBM. In May 1961, Thomas J. Watson Jr. announced a price cut of all 7030s under negotiation to $ 7.78 million and immediate withdrawal of the product from further sales. Its floating-point addition time

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1344-498: The project manager who became a scapegoat when Stretch failed commercially, pointed out soon after the phenomenally successful 1964 launch of System/360 that most of its core concepts were pioneered by Stretch. By 1966, he had received an apology and been made an IBM Fellow, a high honor that carried with it resources and authority to pursue one's desired research. Instruction pipelining , prefetch and decoding, and memory interleaving were used in later supercomputer designs such as

1386-453: The same memory bank by multiple sections of the system (the Computer s, Processor , and I/O DMA Synchronizer s) without conflicts or deadlocks . A memory bank is unavailable for one 4-microsecond cycle after being addressed by any section of the system. If another section attempts to address the same memory bank during this time, it is locked out and must wait, then try again in the next 4-microsecond cycle. To prevent deadlocks and timeouts in

1428-494: The system is booted, the Z-80 is the master and the Xenix boot process initializes the slave 68000, and then transfers control to the 68000, whereupon the CPUs change roles and the Z-80 becomes a slave processor responsible for all I/O operations including disk, communications, printer and network, as well as the keyboard and integrated monitor, while the operating system and applications run on

1470-489: The term multiprocessing for the hardware aspect of having more than one processor. The remainder of this article discusses multiprocessing only in this hardware sense. In Flynn's taxonomy , multiprocessors as defined above are MIMD machines. As the term "multiprocessor" normally refers to tightly coupled systems in which all processors share memory, multiprocessors are not the entire class of MIMD machines, which also contains message passing multicomputer systems. In

1512-499: The then newly invented diffusion transistor . IBM returned to Livermore and stated that they were withdrawing from the contract, and instead proposed a dramatically better system, "We are not going to build that machine for you; we want to build something better! We do not know precisely what it will take but we think it will be another million dollars and another year, and we do not know how fast it will run but we would like to shoot for ten million instructions per second." Livermore

1554-602: The world from 1961 until the first CDC 6600 became operational in 1964. Originally designed to meet a requirement formulated by Edward Teller at Lawrence Livermore National Laboratory , the first example was delivered to Los Alamos National Laboratory in 1961, and a second customized version, the IBM 7950 Harvest , to the National Security Agency in 1962. The Stretch at the Atomic Weapons Research Establishment at Aldermaston , England

1596-412: Was formally initiated. In November 1956, IBM won the contract with the aggressive performance goal of a "speed at least 100 times the IBM 704 " (i.e. 4 MIPS). Delivery was slated for 1960. During design, it proved necessary to reduce the clock speeds, making it clear that Stretch could not meet its aggressive performance goals, but estimates of performance ranged from 60 to 100 times the IBM 704. In 1960,

1638-551: Was heavily used by researchers there and at AERE Harwell , but only after the development of the S2 Fortran compiler which was the first to add dynamic arrays , and which was later ported to the Ferranti Atlas of Atlas Computer Laboratory at Chilton. The 7030 was much slower than expected and failed to meet its aggressive performance goals. IBM was forced to drop its price from $ 13.5 million to only $ 7.78 million and withdrew

1680-676: Was not impressed, and in May 1955 they announced that UNIVAC had won the LARC contract, now called the Livermore Automatic Research Computer . LARC would eventually be delivered in June 1960. In September 1955, fearing that Los Alamos National Laboratory might also order a LARC, IBM submitted a preliminary proposal for a high-performance binary computer based on the improved version of the design that Livermore had rejected, which they received with interest. In January 1956, Project Stretch

1722-401: Was signed. At IBM, a small team at Poughkeepsie including John Griffith and Gene Amdahl worked on the design proposal. Just after they finished and were about to present the proposal, Ralph Palmer stopped them and said, "It's a mistake." The proposed design would have been built with either point-contact transistors or surface-barrier transistors , both likely to be soon outperformed by

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1764-480: Was the fastest computer in 1960–61, until the IBM 7030 took the title. In the basic five-bit biquinary code of the UNIVAC-LARC, 15 combinations are allowed, any one of which may be stored may be stored in any digit position in storage. 5 4 3 2 1 Multiprocessing Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system . The term also refers to

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