A supercomputer is a computer that is considered at the time of its introduction to be at the frontline in terms of processing capacity, particularly speed of calculation. The term "Super Computing" was first used by New York World newspaper in 1929[1] to refer to large custom-built tabulators that IBM had made for Columbia University.
Supercomputers introduced in the 1960s were designed primarily by Seymour Cray at Control Data Corporation (CDC), and led the market into the 1970s until Cray left to form his own company, Cray Research. He then took over the supercomputer market with his new designs, holding the top spot in supercomputing for five years (1985–1990). Cray, himself, never used the word "supercomputer", a little-remembered fact is that he only recognized the word "computer". In the 1980s a large number of smaller competitors entered the market, in a parallel to the creation of the minicomputer market a decade earlier, but many of these disappeared in the mid-1990s "supercomputer market crash". Today, supercomputers are typically one-of-a-kind custom designs produced by "traditional" companies such as IBM and HP, who had purchased many of the 1980s companies to gain their experience
The term supercomputer itself is rather fluid, and today's supercomputer tends to become tomorrow's ordinary computer. CDC's early machines were simply very fast scalar processors, some ten times the speed of the fastest machines offered by other companies. In the 1970s most supercomputers were dedicated to running a vector processor, and many of the newer players developed their own such processors at a lower price to enter the market. The early and mid-1980s saw machines with a modest number of vector processors working in parallel become the standard. Typical numbers of processors were in the range of four to sixteen. In the later 1980s and 1990s, attention turned from vector processors to massive parallel processing systems with thousands of "ordinary" CPUs, some being off the shelf units and others being custom designs. (This is commonly and humorously referred to as the attack of the killer micros in the industry.) Today, parallel designs are based on "off the shelf" server-class microprocessors, such as the PowerPC, Itanium, or x86-64, and most modern supercomputers are now highly-tuned computer clusters using commodity processors combined with custom interconnects.
Software tools
Software tools for distributed processing include standard APIs such as MPI and PVM, and open source-based software solutions such as Beowulf, WareWulf and openMosix which facilitate the creation of a supercomputer from a collection of ordinary workstations or servers. Technology like ZeroConf (Rendezvous/Bonjour) can be used to create ad hoc computer clusters for specialized software such as Apple's Shake compositing application. An easy programming language for supercomputers remains an open research topic in computer science. Several utilities that would once have cost several thousands of dollars are now completely free thanks to the open source community which often creates disruptive technology in this arena.
[edit] Common uses
Supercomputers are used for highly calculation-intensive tasks such as problems involving quantum mechanical physics, weather forecasting, climate research (including research into global warming), molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals), physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion), cryptanalysis, and the like. Major universities, military agencies and scientific research laboratories are heavy users.
A particular class of problems, known as Grand Challenge problems, are problems whose full solution requires semi-infinite computing resources.
Relevant here is the distinction between capability computing and capacity computing, as defined by Graham et al. Capability computing is typically thought of as using the maximum computing power to solve a large problem in the shortest amount of time. Often a capability system is able to solve a problem of a size or complexity that no other computer can. Capacity computing in contrast is typically thought of as using efficient cost-effective computing power to solve somewhat large problems or many small problems or to prepare for a run on a capability system.
[edit] Hardware and software design
Processor board of a CRAY YMP vector computerSupercomputers using custom CPUs traditionally gained their speed over conventional computers through the use of innovative designs that allow them to perform many tasks in parallel, as well as complex detail engineering. They tend to be specialized for certain types of computation, usually numerical calculations, and perform poorly at more general computing tasks. Their memory hierarchy is very carefully designed to ensure the processor is kept fed with data and instructions at all times — in fact, much of the performance difference between slower computers and supercomputers is due to the memory hierarchy. Their I/O systems tend to be designed to support high bandwidth, with latency less of an issue, because supercomputers are not used for transaction processing.
As with all highly parallel systems, Amdahl's law applies, and supercomputer designs devote great effort to eliminating software serialization, and using hardware to address the remaining bottlenecks.
[edit] Supercomputer challenges, technologies
A supercomputer generates large amounts of heat and must be cooled. Cooling most supercomputers is a major HVAC problem.
Information cannot move faster than the speed of light between two parts of a supercomputer. For this reason, a supercomputer that is many meters across must have latencies between its components measured at least in the tens of nanoseconds. Seymour Cray's supercomputer designs attempted to keep cable runs as short as possible for this reason: hence the cylindrical shape of his Cray range of computers. In modern supercomputers built of many conventional CPUs running in parallel, latencies of 1-5 microseconds to send a message between CPUs are typical.
Supercomputers consume and produce massive amounts of data in a very short period of time. According to Ken Batcher, "A supercomputer is a device for turning compute-bound problems into I/O-bound problems." Much work on external storage bandwidth is needed to ensure that this information can be transferred quickly and stored/retrieved correctly.
Technologies developed for supercomputers include:
Vector processing
Liquid cooling
Non-Uniform Memory Access (NUMA)
Striped disks (the first instance of what was later called RAID)
Parallel filesystems
[edit] Processing techniques
Vector processing techniques were first developed for supercomputers and continue to be used in specialist high-performance applications. Vector processing techniques have trickled down to the mass market in DSP architectures and SIMD processing instructions for general-purpose computers.
Modern video game consoles in particular use SIMD extensively and this is the basis for some manufacturers' claim that their game machines are themselves supercomputers. Indeed, some graphics cards have the computing power of several TeraFLOPS. The applications to which this power can be applied was limited by the special-purpose nature of early video processing. As video processing has become more sophisticated, Graphics processing units (GPUs) have evolved to become more useful as general-purpose vector processors, and an entire computer science sub-discipline has arisen to exploit this capability: General-Purpose Computing on Graphics Processing Units (GPGPU).
more : http://en.wikipedia.org/wiki/Supercomputer
Showing posts with label Computer. Show all posts
Showing posts with label Computer. Show all posts
Friday, May 9, 2008
Sunday, April 13, 2008
Computer architecture
In computer engineering, computer architecture is the conceptual design and fundamental operational structure of a computer system. It is a blueprint and functional description of requirements (especially speeds and interconnections) and design implementations for the various parts of a computer — focusing largely on the way by which the central processing unit (CPU) performs internally and accesses addresses in memory.
It may also be defined as the science and art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals.
Computer architecture comprises at least three main subcategories:[1]
Instruction set architecture, or ISA, is the abstract image of a computing system that is seen by a machine language (or assembly language) programmer, including the instruction set, memory address modes, processor registers, and address and data formats.
Microarchitecture, also known as Computer organization is a lower level, more concrete, description of the system that involves how the constituent parts of the system are interconnected and how they interoperate in order to implement the ISA.[2] The size of a computer's cache for instance, is an organizational issue that generally has nothing to do with the ISA.
System Design which includes all of the other hardware components within a computing system such as:
system interconnects such as computer buses and switches
memory controllers and hierarchies
CPU off-load mechanisms such as direct memory access
issues like multi-processing.
Once both ISA and microarchitecture has been specified, the actual device needs to be designed into hardware. This design process is often called implementation. Implementation is usually not considered architectural definition, but rather hardware design engineering.
Implementation can be further broken down into three pieces:
Logic Implementation/Design - where the blocks that were defined in the microarchitecture are implemented as logic equations.
Circuit Implementation/Design - where speed critical blocks or logic equations or logic gates are implemented at the transistor level.
Physical Implementation/Design - where the circuits are drawn out, the different circuit components are placed in a chip floor-plan or on a board and the wires connecting them are routed.
For CPUs, the entire implementation process is often called CPU design.
More specific usages of the term include more general wider-scale hardware architectures, such as cluster computing and Non-Uniform Memory Access (NUMA) architectures
More sub-definitions
Some practioners of computer architecture at companies such as Intel and AMD use more fine distinctions:
Macroarchitecture - architectural layers that are more abstract than microarchitecture, e.g. ISA
ISA (Instruction Set Architecture) - as defined above
Assembly ISA - a smart assembler may convert an abstract assembly language common to a group of machines into slightly different machine language for different implementations
Programmer Visible Macroarchitecture - higher level language tools such as compilers may define a consistent interface or contract to programmers using them, abstracting differences between underlying ISA, UISA, and microarchitectures. E.g. the C, C++, or Java standards define different Programmer Visible Macroarchitecture - although in practice the C microarchitecture for a particular computer includes
UISA (Microcode Instruction Set Architecture) - a family of machines with different hardware level microarchitectures may share a common microcode architecture, and hence a UISA.
Pin Architecture - the set of functions that a microprocessor is expected to provide, from the point of view of a hardware platform. E.g. the x86 A20M, FERR/IGNNE or FLUSH pins, and the messages that the processor is expected to emit after completing a cache invalidation so that external caches can be invalidated. Pin architecture functions are more flexible than ISA functions - external hardware can adapt to changing encodings, or changing from a pin to a message - but the functions are expected to be provided in successive implementations even if the manner of encoding them changes.
[edit] Design goals
The exact form of a computer system depends on the constraints and goals for which it was optimized. Computer architectures usually trade off standards, cost, memory capacity, latency and throughput. Sometimes other considerations, such as features, size, weight, reliability, expandability and power consumption are factors as well.
The most common scheme carefully chooses the bottleneck that most reduces the computer's speed. Ideally, the cost is allocated proportionally to assure that the data rate is nearly the same for all parts of the computer, with the most costly part being the slowest. This is how skillful commercial integrators optimize personal computers.
[edit] Cost
Generally cost is held constant, determined by either system or commercial requirements.
[edit] Performance
Computer performance is often described in terms of clock speed (usually in MHz or GHz). This refers to the cycles per second of the main clock of the CPU. However, this metric is somewhat misleading, as a machine with a higher clock rate may not necessarily have higher performance. As a result manufacturers have moved away from clock speed as a measure of performance. Computer performance can also be measured with the amount of cache a processor has. If the speed, MHz or GHz, were to be a car then the cache is like a traffic light. No matter how fast the car goes, it still will not be stopped by a green traffic light. The higher the speed, and the greater the cache, the faster a processor runs.
Modern CPUs can execute multiple instructions per clock cycle, which dramatically speeds up a program. Other factors influence speed, such as the mix of functional units, bus speeds, available memory, and the type and order of instructions in the programs being run.
There are two main types of speed, latency and throughput. Latency is the time between the start of a process and its completion. Throughput is the amount of work done per unit time. Interrupt latency is the guaranteed maximum response time of the system to an electronic event (e.g. when the disk drive finishes moving some data). Performance is affected by a very wide range of design choices — for example, pipelining a processor usually makes latency worse (slower) but makes throughput better. Computers that control machinery usually need low interrupt latencies. These computers operate in a real-time environment and fail if an operation is not completed in a specified amount of time. For example, computer-controlled anti-lock brakes must begin braking almost immediately after they have been instructed to brake.
The performance of a computer can be measured using other metrics, depending upon its application domain. A system may be CPU bound (as in numerical calculation), I/O bound (as in a webserving application) or memory bound (as in video editing). Power consumption has become important in servers and portable devices like laptops.
Benchmarking tries to take all these factors into account by measuring the time a computer takes to run through a series of test programs. Although benchmarking shows strengths, it may not help one to choose a computer. Often the measured machines split on different measures. For example, one system might handle scientific applications quickly, while another might play popular video games more smoothly. Furthermore, designers have been known to add special features to their products, whether in hardware or software, which permit a specific benchmark to execute quickly but which do not offer similar advantages to other, more general tasks.
[edit] Power consumption
Power consumption is another design criterion that factors in the design of modern computers. Power efficiency can often be traded for performance or cost benefits. With the increasing power density of modern circuits as the number of transistors per chip scales (Moore's Law), power efficiency has increased in importance. Recent processor designs such as the Intel Core 2 put more emphasis on increasing power efficiency. Also, in the world of embedded computing, power efficiency has long been and remains the primary design goal next to performance.
[edit] Historical perspective
Early usage in computer context
The term “architecture” in computer literature can be traced to the work of Lyle R. Johnson and Frederick P. Brooks, Jr., members in 1959 of the Machine Organization department in IBM’s main research center. Johnson had occasion to write a proprietary research communication about Stretch, an IBM-developed supercomputer for Los Alamos Scientific Laboratory; in attempting to characterize his chosen level of detail for discussing the luxuriously embellished computer, he noted that his description of formats, instruction types, hardware parameters, and speed enhancements aimed at the level of “system architecture” – a term that seemed more useful than “machine organization.” Subsequently Brooks, one of the Stretch designers, started Chapter 2 of a book (Planning a Computer System: Project Stretch, ed. W. Buchholz, 1962) by writing, “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” Brooks went on to play a major role in the development of the IBM System/360 line of computers, where “architecture” gained currency as a noun with the definition “what the user needs to know.” Later the computer world would employ the term in many less-explicit ways.
The first mention of the term architecture in the refereed computer literature is in a 1964 article describing the IBM System/360.[3] The article defines architecture as the set of “attributes of a system as seen by the programmer, i.e., the conceptual structure and functional behavior, as distinct from the organization of the data flow and controls, the logical design, and the physical implementation.” In the definition, the programmer perspective of the computer’s functional behavior is key. The conceptual structure part of an architecture description makes the functional behavior comprehensible, and extrapolatable to a range of use cases. Only later on did ‘internals’ such as “the way by which the CPU performs internally and accesses addresses in memory,” mentioned above, slip into the definition of computer architecture.
It may also be defined as the science and art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals.
Computer architecture comprises at least three main subcategories:[1]
Instruction set architecture, or ISA, is the abstract image of a computing system that is seen by a machine language (or assembly language) programmer, including the instruction set, memory address modes, processor registers, and address and data formats.
Microarchitecture, also known as Computer organization is a lower level, more concrete, description of the system that involves how the constituent parts of the system are interconnected and how they interoperate in order to implement the ISA.[2] The size of a computer's cache for instance, is an organizational issue that generally has nothing to do with the ISA.
System Design which includes all of the other hardware components within a computing system such as:
system interconnects such as computer buses and switches
memory controllers and hierarchies
CPU off-load mechanisms such as direct memory access
issues like multi-processing.
Once both ISA and microarchitecture has been specified, the actual device needs to be designed into hardware. This design process is often called implementation. Implementation is usually not considered architectural definition, but rather hardware design engineering.
Implementation can be further broken down into three pieces:
Logic Implementation/Design - where the blocks that were defined in the microarchitecture are implemented as logic equations.
Circuit Implementation/Design - where speed critical blocks or logic equations or logic gates are implemented at the transistor level.
Physical Implementation/Design - where the circuits are drawn out, the different circuit components are placed in a chip floor-plan or on a board and the wires connecting them are routed.
For CPUs, the entire implementation process is often called CPU design.
More specific usages of the term include more general wider-scale hardware architectures, such as cluster computing and Non-Uniform Memory Access (NUMA) architectures
More sub-definitions
Some practioners of computer architecture at companies such as Intel and AMD use more fine distinctions:
Macroarchitecture - architectural layers that are more abstract than microarchitecture, e.g. ISA
ISA (Instruction Set Architecture) - as defined above
Assembly ISA - a smart assembler may convert an abstract assembly language common to a group of machines into slightly different machine language for different implementations
Programmer Visible Macroarchitecture - higher level language tools such as compilers may define a consistent interface or contract to programmers using them, abstracting differences between underlying ISA, UISA, and microarchitectures. E.g. the C, C++, or Java standards define different Programmer Visible Macroarchitecture - although in practice the C microarchitecture for a particular computer includes
UISA (Microcode Instruction Set Architecture) - a family of machines with different hardware level microarchitectures may share a common microcode architecture, and hence a UISA.
Pin Architecture - the set of functions that a microprocessor is expected to provide, from the point of view of a hardware platform. E.g. the x86 A20M, FERR/IGNNE or FLUSH pins, and the messages that the processor is expected to emit after completing a cache invalidation so that external caches can be invalidated. Pin architecture functions are more flexible than ISA functions - external hardware can adapt to changing encodings, or changing from a pin to a message - but the functions are expected to be provided in successive implementations even if the manner of encoding them changes.
[edit] Design goals
The exact form of a computer system depends on the constraints and goals for which it was optimized. Computer architectures usually trade off standards, cost, memory capacity, latency and throughput. Sometimes other considerations, such as features, size, weight, reliability, expandability and power consumption are factors as well.
The most common scheme carefully chooses the bottleneck that most reduces the computer's speed. Ideally, the cost is allocated proportionally to assure that the data rate is nearly the same for all parts of the computer, with the most costly part being the slowest. This is how skillful commercial integrators optimize personal computers.
[edit] Cost
Generally cost is held constant, determined by either system or commercial requirements.
[edit] Performance
Computer performance is often described in terms of clock speed (usually in MHz or GHz). This refers to the cycles per second of the main clock of the CPU. However, this metric is somewhat misleading, as a machine with a higher clock rate may not necessarily have higher performance. As a result manufacturers have moved away from clock speed as a measure of performance. Computer performance can also be measured with the amount of cache a processor has. If the speed, MHz or GHz, were to be a car then the cache is like a traffic light. No matter how fast the car goes, it still will not be stopped by a green traffic light. The higher the speed, and the greater the cache, the faster a processor runs.
Modern CPUs can execute multiple instructions per clock cycle, which dramatically speeds up a program. Other factors influence speed, such as the mix of functional units, bus speeds, available memory, and the type and order of instructions in the programs being run.
There are two main types of speed, latency and throughput. Latency is the time between the start of a process and its completion. Throughput is the amount of work done per unit time. Interrupt latency is the guaranteed maximum response time of the system to an electronic event (e.g. when the disk drive finishes moving some data). Performance is affected by a very wide range of design choices — for example, pipelining a processor usually makes latency worse (slower) but makes throughput better. Computers that control machinery usually need low interrupt latencies. These computers operate in a real-time environment and fail if an operation is not completed in a specified amount of time. For example, computer-controlled anti-lock brakes must begin braking almost immediately after they have been instructed to brake.
The performance of a computer can be measured using other metrics, depending upon its application domain. A system may be CPU bound (as in numerical calculation), I/O bound (as in a webserving application) or memory bound (as in video editing). Power consumption has become important in servers and portable devices like laptops.
Benchmarking tries to take all these factors into account by measuring the time a computer takes to run through a series of test programs. Although benchmarking shows strengths, it may not help one to choose a computer. Often the measured machines split on different measures. For example, one system might handle scientific applications quickly, while another might play popular video games more smoothly. Furthermore, designers have been known to add special features to their products, whether in hardware or software, which permit a specific benchmark to execute quickly but which do not offer similar advantages to other, more general tasks.
[edit] Power consumption
Power consumption is another design criterion that factors in the design of modern computers. Power efficiency can often be traded for performance or cost benefits. With the increasing power density of modern circuits as the number of transistors per chip scales (Moore's Law), power efficiency has increased in importance. Recent processor designs such as the Intel Core 2 put more emphasis on increasing power efficiency. Also, in the world of embedded computing, power efficiency has long been and remains the primary design goal next to performance.
[edit] Historical perspective
Early usage in computer context
The term “architecture” in computer literature can be traced to the work of Lyle R. Johnson and Frederick P. Brooks, Jr., members in 1959 of the Machine Organization department in IBM’s main research center. Johnson had occasion to write a proprietary research communication about Stretch, an IBM-developed supercomputer for Los Alamos Scientific Laboratory; in attempting to characterize his chosen level of detail for discussing the luxuriously embellished computer, he noted that his description of formats, instruction types, hardware parameters, and speed enhancements aimed at the level of “system architecture” – a term that seemed more useful than “machine organization.” Subsequently Brooks, one of the Stretch designers, started Chapter 2 of a book (Planning a Computer System: Project Stretch, ed. W. Buchholz, 1962) by writing, “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” Brooks went on to play a major role in the development of the IBM System/360 line of computers, where “architecture” gained currency as a noun with the definition “what the user needs to know.” Later the computer world would employ the term in many less-explicit ways.
The first mention of the term architecture in the refereed computer literature is in a 1964 article describing the IBM System/360.[3] The article defines architecture as the set of “attributes of a system as seen by the programmer, i.e., the conceptual structure and functional behavior, as distinct from the organization of the data flow and controls, the logical design, and the physical implementation.” In the definition, the programmer perspective of the computer’s functional behavior is key. The conceptual structure part of an architecture description makes the functional behavior comprehensible, and extrapolatable to a range of use cases. Only later on did ‘internals’ such as “the way by which the CPU performs internally and accesses addresses in memory,” mentioned above, slip into the definition of computer architecture.
Computer hardware
Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and hardware data, which are "soft" in the sense that they are readily created, modified or erased on the computer. Firmware is a special type of software that rarely, if ever, needs to be changed and so is stored on hardware devices such as read-only memory (ROM) where it is not readily changed (and is, therefore, "firm" rather than just "soft").
Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003).
Typical PC hardware
A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:
Internals of typical personal computerImage:ASRock K7VT4A Pro Mainboard-eng-labels.jpg
Typical Motherboard found in a computer
Inside a Custom Computer
[edit] Motherboard
Main article: Motherboard
The motherboard is the "heart" of the computer, through which all other components interface.
Central processing unit (CPU) - Performs most of the calculations which enable a computer to function, sometimes referred to as the "brain" of the computer.
Computer fan - Used to lower the temperature of the computer; a fan is almost always attached to the CPU, and the computer case will generally have several fans to maintain a constant airflow. Liquid cooling can also be used to cool a computer, though it focuses more on individual parts rather than the overall temperature inside the chassis.
Random Access Memory (RAM) - Fast-access memory that is cleared when the computer is powered-down. RAM attaches directly to the motherboard, and is used to store programs that are currently running.
Firmware is loaded from the Read only memory ROM run from the Basic Input-Output System (BIOS) or in newer systems Extensible Firmware Interface (EFI) compliant
Internal Buses - Connections to various internal components.
PCI
PCI-E
USB
HyperTransport
CSI (expected in 2008)
AGP (being phased out)
VLB (outdated)
External Bus Controllers - used to connect to external peripherals, such as printers and input devices. These ports may also be based upon expansion cards, attached to the internal buses.
parallel port (outdated)
serial port (outdated)mainbatook
USB
firewire
SCSI (On Servers and older machines)
PS/2 (For mice and keyboards, being phased out and replaced by USB.)
ISA (outdated)
EISA (outdated)
MCA (outdated)
[edit] Power supply
Main article: Computer power supply
A case that holds a transformer, voltage control, and (usually) a cooling fan, and supplies power to run the rest of the computer, the most common types of power supplies are AT and BabyAT (old) but the standard for PC's actually are ATX and micro ATX computer parts or pysical component of computer[batook ake galiey]
[edit] Storage controllers
Controllers for hard disk, CD-ROM and other drives like internal Zip and Jaz conventionally for a PC are IDE/ATA; the controllers sit directly on the motherboard (on-board) or on expansion cards, such as a Disk array controller. IDE is usually integrated, unlike SCSI which is found in most servers. The floppy drive interface is a legacy MFM interface which is now slowly disappearing. All these interfaces are gradually being phased out to be replaced by SATA and SAS.[edited by jent]
[edit] Video display controller
Main article: Graphics card
Produces the output for the visual display unit. This will either be built into the motherboard or attached in its own separate slot (PCI, PCI-E, PCI-E 2.0, or AGP), in the form of a Graphics Card.
[edit] Removable media devices
Main article: Computer storage
CD - the most common type of removable media, inexpensive but has a short life-span.
CD-ROM Drive - a device used for reading data from a CD.
CD Writer - a device used for both reading and writing data to and from a CD.
DVD - a popular type of removable media that is the same dimensions as a CD but stores up to 6 times as much information. It is the most common way of transferring digital video.
DVD-ROM Drive - a device used for reading data from a DVD.
DVD Writer - a device used for both reading and writing data to and from a DVD.
DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
Blu-ray - a high-density optical disc format for the storage of digital information, including high-definition video.
BD-ROM Drive - a device used for reading data from a Blu-ray disc.
BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
HD DVD - a high-density optical disc format and successor to the standard DVD. It was a discontinued competitor to the Blu-ray format.
Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium.
Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable and rewritable.
Tape drive - a device that reads and writes data on a magnetic tape, usually used for long term storage.
[edit] Internal storage
Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.
Hard disk - for medium-term storage of data.
Solid-state drive - a device similar to hard disk, but containing no moving parts.
Disk array controller - a device to manage several hard disks, to achieve performance or reliability improvement.
jent jent je nt\\\
[edit] Sound card
Main article: Sound card
Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade.
[edit] Networking
Main article: Computer networks
Connects the computer to the Internet and/or other computers.
Modem - for dial-up connections
Network card - for DSL/Cable internet, and/or connecting to other computers.
Direct Cable Connection - Use of a null modem, connecting two computers together using their serial ports or a Laplink Cable, connecting two computers together with their parallel ports.
[edit] Other peripherals
Main article: Peripheral
In addition, hardware devices can include external components of a computer system. The following are either standard or very common.
Wheel mouseIncludes various input and output devices, usually external to the computer system
[edit] Input
Main article: Input
Text input devices
Keyboard - a device, to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout.
Pointing devices
Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
Trackball - a pointing device consisting of an exposed portruding ball housed in a socket that detects rotation about two axes.
Xbox 360 Controller - A controller used for Xbox 360, Which with the use of the application Switchblade(tm), Can be used as an additional pointing device with the left or right thumbstick.
Gaming devices
Joystick - a general control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions.
Gamepad - a general game controller held in the hand that relies on the digits (especially thumbs) to provide input.
Game controller - a specific type of controller specialized for certain gaming purposes.
Image, Video input devices
Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
Webcam - a low resolution video camera used to provide visual input that can be easily transferred over the internet.
Audio input devices
Microphone - an acoustic sensor that provides input by converting sound into an electrical signals
and it it usese are important{editedby batook}
[edit] Output
Main article: Output
Image, Video output devices
Printer - a peripheral device that produces a hard (usually paper) copy of a document.
Monitor - device that displays a video signal, similar to a television, to provide the user with information and an interface with which to interact.
Audio output devices
Speakers - a device that converts analog audio signals into the equivalent air vibrations in order to make audible sound.
Headset - a device similar in functionality to computer speakers used mainly to not disturb others nearby.
Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003).
Typical PC hardware
A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:
Internals of typical personal computerImage:ASRock K7VT4A Pro Mainboard-eng-labels.jpg
Typical Motherboard found in a computer
Inside a Custom Computer
[edit] Motherboard
Main article: Motherboard
The motherboard is the "heart" of the computer, through which all other components interface.
Central processing unit (CPU) - Performs most of the calculations which enable a computer to function, sometimes referred to as the "brain" of the computer.
Computer fan - Used to lower the temperature of the computer; a fan is almost always attached to the CPU, and the computer case will generally have several fans to maintain a constant airflow. Liquid cooling can also be used to cool a computer, though it focuses more on individual parts rather than the overall temperature inside the chassis.
Random Access Memory (RAM) - Fast-access memory that is cleared when the computer is powered-down. RAM attaches directly to the motherboard, and is used to store programs that are currently running.
Firmware is loaded from the Read only memory ROM run from the Basic Input-Output System (BIOS) or in newer systems Extensible Firmware Interface (EFI) compliant
Internal Buses - Connections to various internal components.
PCI
PCI-E
USB
HyperTransport
CSI (expected in 2008)
AGP (being phased out)
VLB (outdated)
External Bus Controllers - used to connect to external peripherals, such as printers and input devices. These ports may also be based upon expansion cards, attached to the internal buses.
parallel port (outdated)
serial port (outdated)mainbatook
USB
firewire
SCSI (On Servers and older machines)
PS/2 (For mice and keyboards, being phased out and replaced by USB.)
ISA (outdated)
EISA (outdated)
MCA (outdated)
[edit] Power supply
Main article: Computer power supply
A case that holds a transformer, voltage control, and (usually) a cooling fan, and supplies power to run the rest of the computer, the most common types of power supplies are AT and BabyAT (old) but the standard for PC's actually are ATX and micro ATX computer parts or pysical component of computer[batook ake galiey]
[edit] Storage controllers
Controllers for hard disk, CD-ROM and other drives like internal Zip and Jaz conventionally for a PC are IDE/ATA; the controllers sit directly on the motherboard (on-board) or on expansion cards, such as a Disk array controller. IDE is usually integrated, unlike SCSI which is found in most servers. The floppy drive interface is a legacy MFM interface which is now slowly disappearing. All these interfaces are gradually being phased out to be replaced by SATA and SAS.[edited by jent]
[edit] Video display controller
Main article: Graphics card
Produces the output for the visual display unit. This will either be built into the motherboard or attached in its own separate slot (PCI, PCI-E, PCI-E 2.0, or AGP), in the form of a Graphics Card.
[edit] Removable media devices
Main article: Computer storage
CD - the most common type of removable media, inexpensive but has a short life-span.
CD-ROM Drive - a device used for reading data from a CD.
CD Writer - a device used for both reading and writing data to and from a CD.
DVD - a popular type of removable media that is the same dimensions as a CD but stores up to 6 times as much information. It is the most common way of transferring digital video.
DVD-ROM Drive - a device used for reading data from a DVD.
DVD Writer - a device used for both reading and writing data to and from a DVD.
DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
Blu-ray - a high-density optical disc format for the storage of digital information, including high-definition video.
BD-ROM Drive - a device used for reading data from a Blu-ray disc.
BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
HD DVD - a high-density optical disc format and successor to the standard DVD. It was a discontinued competitor to the Blu-ray format.
Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium.
Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable and rewritable.
Tape drive - a device that reads and writes data on a magnetic tape, usually used for long term storage.
[edit] Internal storage
Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.
Hard disk - for medium-term storage of data.
Solid-state drive - a device similar to hard disk, but containing no moving parts.
Disk array controller - a device to manage several hard disks, to achieve performance or reliability improvement.
jent jent je nt\\\
[edit] Sound card
Main article: Sound card
Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade.
[edit] Networking
Main article: Computer networks
Connects the computer to the Internet and/or other computers.
Modem - for dial-up connections
Network card - for DSL/Cable internet, and/or connecting to other computers.
Direct Cable Connection - Use of a null modem, connecting two computers together using their serial ports or a Laplink Cable, connecting two computers together with their parallel ports.
[edit] Other peripherals
Main article: Peripheral
In addition, hardware devices can include external components of a computer system. The following are either standard or very common.
Wheel mouseIncludes various input and output devices, usually external to the computer system
[edit] Input
Main article: Input
Text input devices
Keyboard - a device, to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout.
Pointing devices
Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
Trackball - a pointing device consisting of an exposed portruding ball housed in a socket that detects rotation about two axes.
Xbox 360 Controller - A controller used for Xbox 360, Which with the use of the application Switchblade(tm), Can be used as an additional pointing device with the left or right thumbstick.
Gaming devices
Joystick - a general control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions.
Gamepad - a general game controller held in the hand that relies on the digits (especially thumbs) to provide input.
Game controller - a specific type of controller specialized for certain gaming purposes.
Image, Video input devices
Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
Webcam - a low resolution video camera used to provide visual input that can be easily transferred over the internet.
Audio input devices
Microphone - an acoustic sensor that provides input by converting sound into an electrical signals
and it it usese are important{editedby batook}
[edit] Output
Main article: Output
Image, Video output devices
Printer - a peripheral device that produces a hard (usually paper) copy of a document.
Monitor - device that displays a video signal, similar to a television, to provide the user with information and an interface with which to interact.
Audio output devices
Speakers - a device that converts analog audio signals into the equivalent air vibrations in order to make audible sound.
Headset - a device similar in functionality to computer speakers used mainly to not disturb others nearby.
Subscribe to:
Posts (Atom)
