Computer hardware
From Wikipedia, the free encyclopedia
For other uses, see Hardware.
that constitutes a computer system. Computer hardwarerefers to the physical parts or components of a computer
such as themonitor, mouse, keyboard, computer data
storage, hard drive disk (HDD), system unit (graphic cards,
sound cards, memory, motherboard and chips), etc.
all of which are physical objects that can be touched.[1]
In contrast, software is instructions that can be stored
and run by hardware.
directs a computer's processor to perform specific
operations. A combination of hardware and software
forms a usable computing system.[2]
operations. A combination of hardware and softwareforms a usable computing system.[2]
Contents
[hide]Von Neumann architecture
Main article: Von Neumann architecture
Different systems[edit]The template for all modern computers is the Von Neumann architecture,
detailed in a 1945 paper by Hungarian
mathematician John von Neumann. This describes a design architecture for an electronic digital computer with
subdivisions of a processing unit consisting of an arithmetic logic unit and processor registers, a control unit
containing an instruction register and program counter, a memory to store both data and instructions, external
mass storage, and input and output mechanisms.[3] The meaning of the term has evolved to mean a stored-program computer in
which an instruction fetch and a data operation cannot occur at the same time because they share a common bus. This is referred
to as the Von Neumann bottleneck and often limits the performance of the system.[4]
detailed in a 1945 paper by Hungarian
mathematician John von Neumann. This describes a design architecture for an electronic digital computer with
subdivisions of a processing unit consisting of an arithmetic logic unit and processor registers, a control unit
containing an instruction register and program counter, a memory to store both data and instructions, external
mass storage, and input and output mechanisms.[3] The meaning of the term has evolved to mean a stored-program computer in
which an instruction fetch and a data operation cannot occur at the same time because they share a common bus. This is referred
to as the Von Neumann bottleneck and often limits the performance of the system.[4]
There are a number of different types of computer system in use today.
Personal computer[edit]
Case[edit]versatility and relatively low price. Laptops are generally
very similar, although may use lower-power or
reduced size components.
Main article: Computer case
The computer case is a plastic or metal enclosure that houses most of the components. Those found
on desktop computers are usually small enough to fit under a desk, but many newer computers us
e more compact designs. Laptops are computers with a clamshell form factor, that fold up into a device
that includes an integrated screen.
on desktop computers are usually small enough to fit under a desk, but many newer computers us
e more compact designs. Laptops are computers with a clamshell form factor, that fold up into a device
that includes an integrated screen.
Power supply[edit]
Main article: Power supply unit (computer)
A power supply unit (PSU) converts alternating current (AC) electric power to low-voltage DC power
for the internal components of the computer. Laptops are capable of running from a built-in battery,
normally for a period of hours.[5]
for the internal components of the computer. Laptops are capable of running from a built-in battery,
normally for a period of hours.[5]
Motherboard[edit]
Main article: Motherboard
The motherboard is the main component inside the case. It is a large rectangular board with integrated
circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives
(CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots.
circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives
(CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots.
Components directly attached to or part of the motherboard include:
- The CPU (Central Processing Unit) performs most of the
- calculations which enable a computer
- to function, and is sometimes referred to as the "brain" of
- the computer. It is usually cooledby
- a heat sink and fan. Most newer CPUs include an on-die
- Graphics Processing Unit (GPU).
- The Chipset, which includes the north bridge, mediates
- communication between the CPU and
- the other components of the system, including main memory.
- The Random-Access Memory (RAM) stores the code and data
- that are being actively accessed
- by the CPU.
- The Read-Only Memory (ROM) stores the BIOS that runs when the computer is powered on or
- otherwise begins execution, a process known as Bootstrapping, or "booting" or "booting up".
- The BIOS (Basic Input Output System) includes boot firmware and power management firmware.
- Newer motherboards use Unified Extensible Firmware Interface (UEFI) instead of BIOS.
- Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
Expansion cards[edit]
Main article: Expansion card
The [expansion card] in computing is a printed circuit board that can be inserted into an expansion
slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.
slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.
Storage devices[edit]
Main article: Computer data storage
Computer data storage, often called storage or memory, refers to computer components and recording
media that retain digital data. Data storage is a core function and fundamental component of computers.
media that retain digital data. Data storage is a core function and fundamental component of computers.
Fixed media
Data is stored by a computer using a variety of media. Hard disk drives are found in virtually all older
computers, due to their high capacity and low cost, but solid-state drives are faster and more power efficient,
although currently more expensive than hard drives, so are often found in more expensive computers.
Some systems may use a disk array controller for greater performance or reliability.
computers, due to their high capacity and low cost, but solid-state drives are faster and more power efficient,
although currently more expensive than hard drives, so are often found in more expensive computers.
Some systems may use a disk array controller for greater performance or reliability.
Removable media
To transfer data between computers, a USB flash drive or Optical disc may be used. Their usefulness
depends on being readable by other systems; the majority of machines have an optical disk drive,
and virtually all have a USB port.
depends on being readable by other systems; the majority of machines have an optical disk drive,
and virtually all have a USB port.
Input and output peripherals[edit]
Main article: Peripheral
Input and output devices are typically housed externally to the main computer chassis.
The following are either standard or very common to many computer systems.
The following are either standard or very common to many computer systems.
Input
Input devices allow the user to enter information into the system, or control its operation.
Most personal computers have a mouse and keyboard, but laptop systems typically use a
touchpad instead of a mouse. Other input devices include webcams, microphones, joysticks,
and image scanners.
Most personal computers have a mouse and keyboard, but laptop systems typically use a
touchpad instead of a mouse. Other input devices include webcams, microphones, joysticks,
and image scanners.
Output device
Output devices display information in a human readable form. Such devices could include printers,
speakers, monitors or a Braille embosser.
speakers, monitors or a Braille embosser.
Mainframe computer[edit]
Supercomputer[edit]A mainframe computer is a much larger computer that typically fills a room and may cost many
hundreds or thousands of times as much as a personal computer. They are designed to perform
large numbers of calculations for governments and large enterprises.
hundreds or thousands of times as much as a personal computer. They are designed to perform
large numbers of calculations for governments and large enterprises.
A supercomputer is superficially similar to a mainframe, but is instead intendedfor extremely
demanding computational tasks. As of November 2013, the fastest supercomputer
in the world is the
Tianhe-2, in Guangzhou, China.[6]
No comments:
Post a Comment