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Stanford DASH
Stanford DASH was a cache coherent multiprocessor developed in the late 1980s by a group led by Anoop Gupta, John L. Hennessy, Mark Horowitz, and Monica S. Lam at Stanford University. It was based on adding a pair of directory boards designed at Stanford to up to 16 SGI IRIS 4D Power Series machines and then cabling the systems in a mesh topology using a Stanford-modified version of the Torus Routing Chip. The boards designed at Stanford implemented a directory-based cache coherence protocol allowing Stanford DASH to support distributed shared memory for up to 64 processors. Stanford DASH was also notable for both supporting and helping to formalize weak memory consistency models, including release consistency. Because Stanford DASH was the first operational machine to include scalable cache coherence, it influenced subsequent computer science research as well as the commercially available SGI Origin 2000. Stanford DASH is included in the 25th anniversary retrospective of selected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, which is particularly the case with CPUs in a multiprocessing system. In the illustration on the right, consider both the clients have a cached copy of a particular memory block from a previous read. Suppose the client on the bottom updates/changes that memory block, the client on the top could be left with an invalid cache of memory without any notification of the change. Cache coherence is intended to manage such conflicts by maintaining a coherent view of the data values in multiple caches. Overview In a shared memory multiprocessor system with a separate cache memory for each processor, it is possible to have many copies of shared data: one copy in the main memory and one in the local cache of each processor that requested it. When one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiprocessor
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 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, 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 the operating system level, ''multiprocessing'' is som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John L
John Lasarus Williams (29 October 1924 – 15 June 2004), known as John L, was a Welsh nationalist activist. Williams was born in Llangoed on Anglesey, but lived most of his life in nearby Llanfairpwllgwyngyll. In his youth, he was a keen footballer, and he also worked as a teacher. His activism started when he campaigned against the refusal of Brewer Spinks, an employer in Blaenau Ffestiniog, to permit his staff to speak Welsh. This inspired him to become a founder of Undeb y Gymraeg Fyw, and through this organisation was the main organiser of ''Sioe Gymraeg y Borth'' (the Welsh show for Menai Bridge using the colloquial form of its Welsh name).Colli John L Williams , '''', 15 June ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark Horowitz
Mark A. Horowitz is the Yahoo! Founders Professor in the School of Engineering at Stanford University and holds a joint appointment in the Electrical Engineering and Computer Science department. He is a co-founder of Rambus Inc., now a technology licensing company. Education Horowitz received bachelor's and master's degrees in electrical engineering from the Massachusetts Institute of Technology in 1978. After graduating, he moved to Silicon Valley to work at Signetics, one of the early integrated circuits companies. After working for a year, he entered Stanford, and worked on CAD tools for very-large-scale integration (VLSI) design. His research at Stanford included some of the earliest work on extracting the resistance of integrated circuit wires, and estimating the delay of MOS transistor circuits. He was advised at Stanford by Robert Dutton and graduated with a Ph.D. in electrical engineering in 1984. Academic career In 1984, Horowitz joined the Stanford faculty. At Stanfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monica S
Monica may refer to: People *Monica (actress) (born 1987), Indian film actress *Monica (given name), a given name (including a list of people and characters with the name) *Monica (singer) (born 1980), American R&B singer, songwriter, producer, and actress *Saint Monica, mother of Augustine Places * 833 Monica, a minor planet * Monica, Kentucky * Santa Monica, California Arts, entertainment, and media Fiction * ''Monica'' (2011 film), an Indian film * ''Monica'' (2022 film), an American-Italian film *Monica, a fictional country in ''Æon Flux'' *Monica, a fictional planet in David Weber's science fiction Honorverse Music * MONICA, a Scottish band featuring members of Win/ The Apples and Trembling Bells * "Monica" (song), a song by The Kinks from their album ''The Kinks Are the Village Green Preservation Society'' (1968) *"Monica", a song by Dan Bern from his album ''Fifty Eggs'' *"Monica", a 1984 song by Kōji Kikkawa **Leslie Cheung, covered into Cantonese in 1984 ** Leo K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford University
Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is considered among the most prestigious universities in the world. Stanford was founded in 1885 by Leland and Jane Stanford in memory of their only child, Leland Stanford Jr., who had died of typhoid fever at age 15 the previous year. Leland Stanford was a U.S. senator and former governor of California who made his fortune as a railroad tycoon. The school admitted its first students on October 1, 1891, as a coeducational and non-denominational institution. Stanford University struggled financially after the death of Leland Stanford in 1893 and again after much of the campus was damaged by the 1906 San Francisco earthquake. Following World War II, provost of Stanford Frederick Terman inspired and supported faculty and graduates' entrepreneu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SGI IRIS 4D
The SGI IRIS series of terminals and workstations from Silicon Graphics was produced in the 1980s and 1990s. IRIS is an acronym for Integrated Raster Imaging System. Overview 68000 The early systems up to IRIS 3000 use the Motorola 68000 series of processors originally, and later models feature early-generation MIPS processors. These systems run the GL2 operating system, a predecessor of the IRIX operating system, which is based on UniSoft UniPlus System V Unix. GL2 uses a proprietary windowing system named mex (Multiple EXposure). The first model, the IRIS 1000, was shipped around November 1983 with an 8 MHz Motorola 68000 CPU. It is a graphics terminal intended to be attached to a VAX-11 system running either VAX/VMS or BSD Unix. The related IRIS 1200 terminal has a 20-slot backplane in its cabinet versus the 10-slot backplane of the IRIS 1000. The IRIS 1400 Workstation (also known as the IRIS Workstation) was shipped only in 1984. It has a 10 MHz Motorola 68010. MIPS Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cache Coherence
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, which is particularly the case with CPUs in a multiprocessing system. In the illustration on the right, consider both the clients have a cached copy of a particular memory block from a previous read. Suppose the client on the bottom updates/changes that memory block, the client on the top could be left with an invalid cache of memory without any notification of the change. Cache coherence is intended to manage such conflicts by maintaining a coherent view of the data values in multiple caches. Overview In a shared memory multiprocessor system with a separate cache memory for each processor, it is possible to have many copies of shared data: one copy in the main memory and one in the local cache of each processor that requested it. When on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Shared Memory
In computer science, distributed shared memory (DSM) is a form of memory architecture where physically separated memories can be addressed as a single shared address space. The term "shared" does not mean that there is a single centralized memory, but that the address space is shared—i.e., the same physical address on two processors refers to the same location in memory. Distributed global address space (DGAS), is a similar term for a wide class of software and hardware implementations, in which each node of a cluster has access to shared memory in addition to each node's private (i.e., not shared) memory. Overview A distributed-memory system, often called a multicomputer, consists of multiple independent processing nodes with local memory modules which is connected by a general interconnection network. Software DSM systems can be implemented in an operating system, or as a programming library and can be thought of as extensions of the underlying virtual memory architecture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consistency Model
In computer science, a consistency model specifies a contract between the programmer and a system, wherein the system guarantees that if the programmer follows the rules for operations on memory, memory will be consistent and the results of reading, writing, or updating memory will be predictable. Consistency models are used in distributed systems like distributed shared memory systems or distributed data stores (such as filesystems, databases, optimistic replication systems or web caching). Consistency is different from coherence, which occurs in systems that are cached or cache-less, and is consistency of data with respect to all processors. Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors. High level languages, such as C++ and Java, maintain the consistency contract by translating memory operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Release Consistency
Release consistency is one of the synchronization-based consistency models used in concurrent programming (e.g. in distributed shared memory, distributed transactions etc.). Introduction In modern parallel computing systems, memory consistency must be maintained to avoid undesirable outcomes. Strict consistency models like sequential consistency are intuitively composed but can be quite restrictive in terms of performance as they would disable instruction level parallelism which is widely applied in sequential programming. To achieve better performance, some relaxed models are explored and release consistency is an aggressive relaxing attempt. Release consistency vs. sequential consistency Hardware structure and program-level effort Sequential consistency can be achieved simply by hardware implementation, while release consistency is also based on an observation that most of the parallel programs are properly synchronized. In programming level, synchronization is applied to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SGI Origin 2000
The SGI Origin 2000 is a family of mid-range and high-end server computers developed and manufactured by Silicon Graphics (SGI). They were introduced in 1996 to succeed the SGI Challenge and POWER Challenge. At the time of introduction, these ran the IRIX operating system, originally version 6.4 and later, 6.5. A variant of the Origin 2000 with graphics capability is known as the Onyx2. An entry-level variant based on the same architecture but with a different hardware implementation is known as the Origin 200. The Origin 2000 was succeeded by the Origin 3000 in July 2000, and was discontinued on June 30, 2002. Models The family was announced on October 7, 1996. The project was code named ''Lego'', and also known as SN0, to indicate the first in a series of scalable node architectures, contrasting with previous symmetric multiprocessor architectures in the SGI Challenge series. The Origin 2100 is mostly the same as the other models except that it is not upgradeable to other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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