Commodity computing (also known as commodity cluster computing) involves the use of large numbers of already-available computing components for parallel computing, to get the greatest amount of useful computation at low cost. [1] This is a useful alternative to high-cost superminicomputers or boutique computers. Commodity computers are computer systems - manufactured by multiple vendors - incorporating components based on open standards.[ citation needed ]
Such systems are said[ by whom? ] to be based on standardized computer components, since the standardization process promotes lower costs and less differentiation among vendors' products. Standardization and decreased differentiation lower the switching or exit cost from any given vendor, increasing purchasers' leverage and preventing lock-in.
A governing principle of commodity computing is that it is preferable to have more low-performance, low-cost hardware working in parallel (scalar computing) (e.g. AMD x86 CISC [2] ) than to have fewer high-performance, high-cost hardware items [3] (e.g. IBM POWER7 or Sun-Oracle's SPARC [4] RISC). At some point, the number of discrete systems in a cluster will be greater than the mean time between failures (MTBF) for any hardware platform[ dubious – discuss ], no matter how reliable, so fault tolerance must be built into the controlling software. [5] [6] Purchases should be optimized on cost-per-unit-of-performance, not just on absolute performance-per-CPU at any cost.[ citation needed ]
The first computers were large, expensive and proprietary. The move towards commodity computing began when DEC introduced the PDP-8 in 1965. This was a computer that was relatively small and inexpensive enough that a department could purchase one without convening a meeting of the board of directors. The entire minicomputer industry sprang up to supply the demand for 'small' computers like the PDP-8. Unfortunately, each of the many different brands of minicomputers had to stand on its own because there was no software and very little hardware compatibility between the brands.
When the first general purpose microprocessor was introduced in 1971 (Intel 4004) it immediately began chipping away at the low end of the computer market, replacing embedded minicomputers in many industrial devices.
This process accelerated in 1977 with the introduction of the first commodity-like microcomputer, the Apple II. With the development of the VisiCalc application in 1979, microcomputers broke out of the factory and began entering office suites in large quantities, but still through the back door.
The IBM PC was introduced in 1981 and immediately began displacing Apple II systems in the corporate world, but commodity computing as we know it today truly began when Compaq developed the first true IBM PC compatible. More and more PC-compatible microcomputers began coming into big companies through the front door and commodity computing was well established.
During the 1980s, microcomputers began displacing larger computers in a serious way. At first, price was the key justification but by the late 1980s and early 1990s, VLSI semiconductor technology had evolved to the point where microprocessor performance began to eclipse the performance of discrete logic designs. These traditional designs were limited by speed-of-light delay issues inherent in any CPU larger than a single chip, and performance alone began driving the success of microprocessor-based systems.
By the mid-1990s, nearly all computers made were based on microprocessors, and the majority of general purpose microprocessors were implementations of the x86 instruction set architecture. Although there was a time when every traditional computer manufacturer had its own proprietary micro-based designs, there are only a few manufacturers of non-commodity computer systems today.
Today, there are fewer and fewer general business computing requirements that cannot be met with off-the-shelf commodity computers. It is likely that the low-end of the supermicrocomputer genre will continue to be pushed upward by increasingly powerful commodity microcomputers.
A central processing unit (CPU), also called a central processor, main processor, or just processor, is the most important processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, logic, controlling, and input/output (I/O) operations. This role contrasts with that of external components, such as main memory and I/O circuitry, and specialized coprocessors such as graphics processing units (GPUs).
The IBM Personal Computer is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team of engineers and designers at International Business Machines (IBM), directed by William C. Lowe and Philip Don Estridge in Boca Raton, Florida.
A microprocessor is a computer processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit (CPU). The IC is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, clock-driven, register-based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output. Microprocessors contain both combinational logic and sequential digital logic, and operate on numbers and symbols represented in the binary number system.
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers.
A minicomputer, or colloquially mini, is a type of smaller general-purpose computer developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, The New York Times suggested a consensus definition of a minicomputer as a machine costing less than US$25,000, with an input-output device such as a teleprinter and at least four thousand words of memory, that is capable of running programs in a higher level language, such as Fortran or BASIC.
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers, were comparatively much larger and more expensive. Many microcomputers are also personal computers. An early use of the term "personal computer" in 1962 predates microprocessor-based designs. (See "Personal Computer: Computers at Companies" reference below). A "microcomputer" used as an embedded control system may have no human-readable input and output devices. "Personal computer" may be used generically or may denote an IBM PC compatible machine.
"IBM PC–compatible" refers to a class of computers that are technically compatible with the 1981 IBM PC and subsequent XT and AT models from computer giant IBM. Like the original IBM PC, they use an Intel x86 central processing unit and are capable of using interchangeable commodity hardware, such as expansion cards. Initially such computers were referred to as PC clones, IBM clones or IBM PC clones, but the term "IBM PC compatible" is now a historical description only, as the vast majority of microcomputers produced since the 1990s are IBM compatible. IBM itself no longer sells personal computers, having sold its division to Lenovo in 2005. "Wintel" is a similar description that is more commonly used for modern computers.
A desktop computer is a personal computer designed for regular use at a stationary location on or near a desk due to its size and power requirements. The most common configuration has a case that houses the power supply, motherboard, disk storage ; a keyboard and mouse for input; and a monitor, speakers, and, often, a printer for output. The case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk.
A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating systems. The term workstation has been used loosely to refer to everything from a mainframe computer terminal to a PC connected to a network, but the most common form refers to the class of hardware offered by several current and defunct companies such as Sun Microsystems, Silicon Graphics, Apollo Computer, DEC, HP, NeXT, and IBM which powered the 3D computer graphics revolution of the late 1990s.
The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as transistors and then integrated circuit (IC) chips. Around 1953 to 1959, discrete transistors started being considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology subsequently led to the development of semiconductor memory in the mid-to-late 1960s and then the microprocessor in the early 1970s. This led to primary computer memory moving away from magnetic-core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size, and power consumption of computers. These advances led to the miniaturized personal computer (PC) in the 1970s, starting with home computers and desktop computers, followed by laptops and then mobile computers over the next several decades.
Project Athena was a joint project of MIT, Digital Equipment Corporation, and IBM to produce a campus-wide distributed computing environment for educational use. It was launched in 1983, and research and development ran until June 30, 1991. As of 2023, Athena is still in production use at MIT. It works as software that makes a machine a thin client, that will download educational applications from the MIT servers on demand.
A blade server is a stripped-down server computer with a modular design optimized to minimize the use of physical space and energy. Blade servers have many components removed to save space, minimize power consumption and other considerations, while still having all the functional components to be considered a computer. Unlike a rack-mount server, a blade server fits inside a blade enclosure, which can hold multiple blade servers, providing services such as power, cooling, networking, various interconnects and management. Together, blades and the blade enclosure form a blade system, which may itself be rack-mounted. Different blade providers have differing principles regarding what to include in the blade itself, and in the blade system as a whole.
Midrange computers, or midrange systems, were a class of computer systems that fell in between mainframe computers and microcomputers.
The history of general-purpose CPUs is a continuation of the earlier history of computing hardware.
Following the introduction of the IBM Personal Computer, or IBM PC, many other personal computer architectures became extinct within just a few years. It led to a wave of IBM PC compatible systems being released.
In computing, performance per watt is a measure of the energy efficiency of a particular computer architecture or computer hardware. Literally, it measures the rate of computation that can be delivered by a computer for every watt of power consumed. This rate is typically measured by performance on the LINPACK benchmark when trying to compare between computing systems: an example using this is the Green500 list of supercomputers. Performance per watt has been suggested to be a more sustainable measure of computing than Moore's Law.
The history of the personal computer as a mass-market consumer electronic device began with the microcomputer revolution of the 1970s. A personal computer is one intended for interactive individual use, as opposed to a mainframe computer where the end user's requests are filtered through operating staff, or a time-sharing system in which one large processor is shared by many individuals. After the development of the microprocessor, individual personal computers were low enough in cost that they eventually became affordable consumer goods. Early personal computers – generally called microcomputers – were sold often in electronic kit form and in limited numbers, and were of interest mostly to hobbyists and technicians.
A personal computer, often referred to as a PC, is a computer designed for individual use. It is typically used for tasks such as word processing, internet browsing, email, multimedia playback, and gaming. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. The term home computer has also been used, primarily in the late 1970s and 1980s. The advent of personal computers and the concurrent Digital Revolution have significantly affected the lives of people.
A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software. The newest manifestation of cluster computing is cloud computing.
Computers can be classified, or typed, in many ways. Some common classifications of computers are given below.
The purpose of commodity cluster computing is to utilize large numbers of readily available computing components for parallel computing to obtaining the greatest amount of useful computations for the least cost. The issue of the cost of a computational resource is key to computational science and data processing at GSFC as it is at most other places, the difference being that the need at GSFC far exceeds any expectation of meeting that need.