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A motherboard is the central printed circuit board (PCB) in some complex electronic systems, such as modern personal computers. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple computers, the logic board.It is also sometimes casually shortened to mobo.

Overview

An Acer E360 motherboard made by Foxconn, from 2005, with a large number of integrated peripherals. This board’s nForce3 chipset lacks a traditional northbridge.

Most computer motherboards produced today are designed for IBM-compatible computers, which currently account for around 90% of global PC sales. A motherboard, like a backplane, provides the electrical connections by which the other components of the system communicate, but unlike a backplane, it also hosts the central processing unit, and other subsystems and devices.

Motherboards are also used in many other electronics devices.

A typical desktop computer has its microprocessor, main memory, and other essential components on the motherboard. Other components such as external storage, controllers for video display and sound, and peripheral devices may be attached to the motherboard as plug-in cards or via cables, although in modern computers it is increasingly common to integrate some of these peripherals into the motherboard itself.

An important component of a motherboard is the microprocessor’s supporting chipset, which provides the supporting interfaces between the CPU and the various buses and external components. This chipset determines, to an extent, the features and capabilities of the motherboard.

Modern motherboards include, at a minimum:

• sockets (or slots) in which one or more microprocessors are installed
• slots into which the system’s main memory is installed (typically in the form of DIMM modules containing DRAM chips)
• a chipset which forms an interface between the CPU’s front-side bus, main memory, and peripheral buses
• non-volatile memory chips (usually Flash ROM in modern motherboards) containing the system’s firmware or BIOS
• a clock generator which produces the system clock signal to synchronize the various components
• slots for expansion cards (these interface to the system via the buses supported by the chipset)
• power connectors flickers, which receive electrical power from the computer power supply and distribute it to the CPU, chipset, main memory, and expansion cards.

The Octek Jaguar V motherboard from 1993.This board has 6 ISA slots but few onboard peripherals, as evidenced by the lack of external connectors.

Additionally, nearly all motherboards include logic and connectors to support commonly-used input devices, such as PS/2 connectors for a mouse and keyboard. Early personal computers such as the Apple II or IBM PC included only this minimal peripheral support on the motherboard. Occasionally video interface hardware was also integrated into the motherboard; for example on the Apple II, and rarely on IBM-compatible computers such as the IBM PC Jr. Additional peripherals such as disk controllers and serial ports were provided as expansion cards.

Given the high thermal design power of high-speed computer CPUs and components, modern motherboards nearly always include heatsinks and mounting points for fans to dissipate excess heat.

CPU sockets

Integrated peripherals

Block diagram of a modern motherboard, which supports many on-board peripheral functions as well as several expansion slots.

With the steadily declining costs and size of integrated circuits, it is now possible to include support for many peripherals on the motherboard. By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly-integrated motherboards are thus especially popular in small form factor and budget computers.

For example, the ECS RS485M-M, a typical modern budget motherboard for computers based on AMD processors, has on-board support for a very large range of peripherals:

• disk controllers for a floppy disk drive, up to 2 PATA drives, and up to 6 SATA drives (including RAID 0/1 support)
• integrated ATI Radeon graphics controller supporting 2D and 3D graphics, with VGA and TV output
• integrated sound card supporting 8-channel (7.1) audio and S/PDIF output
• fast Ethernet network controller for 10/100 Mbit networking
• USB 2.0 controller supporting up to 12 USB ports
• IrDA controller for infrared data communication (e.g. with an IrDA enabled Cellular Phone or Printer)
• temperature, voltage, and fan-speed sensors that allow software to monitor the health of computer components

Expansion cards to support all of these functions would have cost hundreds of dollars even a decade ago, however as of April 2007^[update] such highly-integrated motherboards are available for as little as $30 in the USA.

Peripheral card slots

A typical motherboard of 2007 will have a different number of connections depending on its standard. A standard ATX motherboard will typically have 1x PCI-E 16x connection for a graphics card, 2x PCI slots for various expansion cards and 1x PCI-E 1x which will eventually supersede PCI.

A standard Super ATX motherboard will have 1x PCI-E 16x connection for a graphics card. It will also have a varying number of PCI and PCI-E 1x slots. It can sometimes also have a PCI-E 4x slot. This varies between brands and models.

Some motherboards have 2x PCI-E 16x slots, to allow more than 2 monitors without special hardware or to allow use of a special graphics technology called SLI (for Nvidia) and Crossfire (for ATI). These allow 2 graphics cards to be linked together, to allow better performance in intensive graphical computing tasks, such as gaming and video-editing.

As of 2007^[update], virtually all motherboards come with at least 4x USB ports on the rear, with at least 2 connections on the board internally for wiring additional front ports that are built into the computer’s case. Ethernet is also included now. This is a standard networking cable for connecting the computer to a network or a modem. A sound chip is always included on the motherboard, to allow sound to be output without the need for any extra components. This allows computers to be far more multimedia-based than before. Cheaper machines now often have their graphics chip built into the motherboard rather than a separate card.

Temperature and reliability

Motherboards are generally air cooled with heat sinks often mounted on larger chips, such as the northbridge, in modern motherboards. If the motherboard is not cooled properly, then this can cause its computer to crash. Passive cooling, or a single fan mounted on the power supply, was sufficient for many desktop computer CPUs until the late 1990s; since then, most have required CPU fans mounted on their heatsinks, due to rising clock speeds and power consumption. Most motherboards have connectors for additional case fans as well. Newer motherboards have integrated temperature sensors to detect motherboard and CPU temperatures, and controllable fan connectors which the BIOS or operating system can use to regulate fan speed. Some higher-powered computers (which typically have high-performance processors and large amounts of RAM, as well as high-performance video cards) use a water-cooling system instead of many fans.

Some small form factor computers and home theater PCs designed for quiet and energy-efficient operation boast fan-less designs. This typically requires the use of a low-power CPU, as well as careful layout of the motherboard and other components to allow for heat sink placement.

A 2003 study found that some spurious computer crashes and general reliability issues, ranging from screen image distortions to I/O read/write errors, can be attributed not to software or peripheral hardware but to aging capacitors on PC motherboards. Ultimately this was shown to be the result of a faulty electrolyte formulation.

Motherboards use electrolytic capacitors to filter the DC power distributed around the board. These capacitors age at a temperature-dependent rate, as their water based electrolytes slowly evaporate. This can lead to loss of capacitance and subsequent motherboard malfunctions due to voltage instabilities. While most capacitors are rated for 2000 hours of operation at 105 °C, their expected design life roughly doubles for every 10 °C below this. At 45 °C a lifetime of 15 years can be expected. This appears reasonable for a computer motherboard, however many manufacturers have delivered substandard capacitors,which significantly reduce life expectancy. Inadequate case cooling and elevated temperatures easily exacerbate this problem. It is possible, but tedious and time-consuming, to find and replace failed capacitors on PC motherboards; it is less expensive to buy a new motherboard than to pay for such a repair.

Form factor

microATX form factor motherboard

Motherboards are produced in a variety of sizes and shapes (”form factors”), some of which are specific to individual computer manufacturers. However, the motherboards used in IBM-compatible commodity computers have been standardized to fit various case sizes. As of 2007^[update], most desktop computer motherboards use one of these standard form factors—even those found in Macintosh and Sun computers which have not traditionally been built from commodity components.

Laptop computers generally use highly integrated, miniaturized, and customized motherboards. This is one of the reasons that laptop computers are difficult to upgrade and expensive to repair. Often the failure of one laptop component requires the replacement of the entire motherboard, which is usually more expensive than a desktop motherboard due to the large number of integrated components.

Nvidia SLI and ATI Crossfire

Nvidia SLI and ATI Crossfire technology allows 2 or more of the same series graphics cards to be linked together to allow a faster graphics experience. Almost all medium to high end Nvidia cards and most high end ATI cards support the technology.

They both require compatible motherboards. There is an obvious need for 2x PCI-E 16x slots to allow 2 cards to be inserted into the computer. The same function can be achieved in 650i motherboards by NVIDIA, with a pair of x8 slots. Originally, tri-Crossfire was achieved at 8x speeds with 2 16x slots and 1 8x slot albeit at a slower speed. ATI opened the technology up to Intel in 2006 and such all new Intel chipsets support Crossfire.

SLI is a little more proprietary in its needs. It requires a motherboard with Nvidia’s own NForce chipset series to allow it to run (exception: Intel X58 chipset).

It is important to note that SLI and Crossfire will not usually scale to 2x the performance of a single card when using a dual setup. They also do not double the effective amount of VRAM or memory bandwidth.

History

Prior to the advent of the microprocessor, a computer was usually built in a card-cage case or mainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed-circuit boards soon became the standard practice. The central processing unit, memory and peripherals were housed on individual printed circuit boards which plugged into the backplane.

During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard (see above). In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. As of the late 1990s, many personal computer motherboards support a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-end systems for 3D gaming and computer graphics typically retain only the graphics card as a separate component.

The early pioneers of motherboard manufacturing were Micronics, Mylex, AMI, DTK, Hauppauge, Orchid Technology, Elitegroup, DFI, and a number of Taiwan-based manufacturers.

Popular personal computers such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse-engineering and third-party replacement motherboards. Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer’s original equipment.

The term mainboard is archaically applied to devices with a single board and no additional expansions or capability. In modern terms this would include embedded systems, and controlling boards in televisions, washing machines etc. A motherboard specifically refers to a printed circuit with the capability to add/extend its performance/capabailities with the addition of “daughterboards”.

Bootstrapping using the BIOS

Motherboards contain some non-volatile memory to initialize the system and load an operating system from some external peripheral device. Microcomputers such as the Apple II and IBM PC used read-only memory chips, mounted in sockets on the motherboard. At power-up, the central processor would load its program counter with the address of the boot ROM, and start executing ROM instructions, displaying system information on the screen and running memory checks, which would in turn start loading memory from an external or peripheral device (disk drive). If none is available, then the computer can perform tasks from other memory stores or display an error message, depending on the model and design of the computer and version of the BIOS.

Most modern motherboard designs use a BIOS, stored in an EEPROM chip soldered to the motherboard, to bootstrap the motherboard. (Socketed BIOS chips are widely used, also.) By booting the motherboard, the memory, circuitry, and peripherals are tested and configured. This process is known as a computer Power-On Self Test (POST) and may include testing some of the following devices:

• floppy drive
• network controller
• CD-ROM drive
• DVD-ROM drive
• SCSI hard drive
• IDE, EIDE, or SATA hard drive
• External USB memory storage device

Any of the above devices can be stored with machine code instructions to load an operating system or a program.

“wikipedia.org”

main article-Wikipedia

The top cover has been removed to show the internals of a computer Power supply Unit.

A power supply unit (PSU) is the component that supplies power to a computer. More specifically, a power supply is typically designed to convert 100-120 V (North America and Japan) or 220-240 V (New Zealand, Europe, South America, Africa, Asia and Australia) AC power from the mains to usable low-voltage DC power for the internal components of the computer. Some power supplies have a switch to change between 230 V and 115 V. Other models have automatic sensors that switch input voltage automatically, or are able to accept any voltage between those limits.

The most common computer power supplies are built to conform with the ATX form factor. The most recent specification of the ATX standard PSU as of mid-2008 is version 2.31. This enables different power supplies to be interchangeable with different components inside the computer. ATX power supplies also are designed to turn on and off using a signal from the motherboard, and provide support for modern functions such as the standby mode available in many computers.

Passive heat sink cooling

Passive heatsink fitted on a Intel GMA graphics chip

This involves attaching a block of machined metal to the part that needs cooling. An adhesive may be used, or more commonly for a personal computer CPU, a clamp is used to affix the heat sink right over the chip, with a thermally conductive pad or gel spread in-between. This block usually has fins and ridges to increase its surface area. The heat conductivity of metal is much better than that of air, and its ability to radiate heat is better than that of the component part it is protecting (usually an integrated circuit or CPU). Until recently, fan cooled aluminium heat sinks were the norm for desktop computers. Today many heat sinks feature copper base-plates or are entirely made of copper, and mount fans of considerable size and power.

Heat sinks tend to get less effective with time due to the build up of dust between their metal fins, which reduces the efficiency with which the heat sink transfers heat to the ambient air. Dust build up is commonly countered with canned air, which is used to blow away the dust along with any other unwanted excess material.

Passive heat sinks are commonly found on older CPUs, parts that do not get very hot (such as the chipset), and low-power computers.

Active heat sink cooling

This uses the same principle as a passive heat sink cooler, with the only difference being that a fan is directed to blow over or through the heat sink. This results in more air being blown through the heat sink, increasing the rate at which the heat sink can exchange heat with the ambient air. Active heat sinks are the primary method of cooling a modern day processor or graphics card.

The buildup of dust is greatly increased with active heat sink cooling as the fan is continually taking in the dust present in the surrounding air. As a result, dust removal procedures need to be exercised much more frequently than with passive heat sink methods.

Peltier cooling or thermoelectric cooling

In 1821 T. J. Seebeck discovered that different metals, connected at two different junctions, will develop a micro-voltage if the two junctions are held at different temperatures. This effect is known as the “Seebeck effect”; it is the basic theory behind the TEC (thermoelectric cooling).

In 1834 Jean Peltier discovered the inverse of the Seebeck effect, now known as the “Peltier effect”. He found that applying a voltage to a thermocouple creates a temperature differential between two sides. This results in an effective, albeit extremely inefficient heat pump.

Modern TECs use several stacked units each composed of dozens or hundreds of thermocouples laid out next to each other, which allows for a substantial amount of heat transfer. A combination of bismuth and telluride is most commonly used for thermocouples.

Since TECs are active heat pumps, they are capable of cooling PC components below ambient temperatures, which is impossible with common radiator cooled water cooling systems and heatpipe HSFs.

Heatsink n Fan     Watecooling reservoir   Watercooling System

Water cooling

DIY Watercooling setup showing 12v pump, CPU Waterblock and the typical application of a T-Line.

While originally limited to mainframe computers, computer watercooling has become a practice largely associated with overclocking in the form of either manufactured “kits” or in the form of DIY setups assembled from individually gathered parts. Lately watercooling has seen increasing use in pre-assembled desktop computers. Water cooling can extract more heat from the cooled parts, which makes it suitable for overclocking, and opposed to air cooling it is less influenced by the ambient temperature. One of its disadvantages is the potential for a coolant leak, which can damage electronic components. An advantage is that a water cooling system is not limited to one component, so it can cool the CPU, GPU and other components at the same time. Another advantage to water cooling is the low noise-level output it provides when compared to that of fan cooling, which can become loud especially when using a higher clock rate processor.

Heat pipe

A heat pipe is a hollow tube containing a heat transfer liquid. As the liquid evaporates, it carries heat to the cool end, where it condenses and then returns to the hot end (under capillary action). Heat pipes thus have a much higher effective thermal conductivity than solid materials. For use in computers, the heat sink on the CPU is attached to a larger radiator heat sink. Both heat sinks are hollow as is the attachment between them, creating one large heat pipe that transfers heat from the CPU to the radiator, which is then cooled using some conventional method. This method is expensive and usually used when space is tight (as in small form-factor PCs), or absolute quiet is needed (such as in computers used in audio production studios during live recording).

Phase-change cooling

Phase-change cooling is an extremely effective way to cool the processor. A vapor compression phase-change cooler is a unit which usually sits underneath the PC, with a tube leading to the processor. Inside the unit is a compressor, the same type that cools a freezer. The compressor compresses a gas (or mixture of gases) which condenses it into a liquid. Then, the liquid is pumped up to the processor, where it passes through an expansion device, this can be from a simple capillary tube to a more elaborate thermal expansion valve. The liquid evaporates (changing phase), absorbing the heat from the processor as it draws extra energy from its environment to accommodate this change. The evaporation can produce temperatures reaching around −15 to -150  degrees Celsius. The gas flows down to the compressor and the cycle begins over again. This way, the processor can be cooled to temperatures ranging from −15 to −150  degrees Celsius, depending on the load, wattage of the processor, the refrigeration system and the gas mixture used. This type of system suffers from a number of issues but mainly one must be concerned with dew point and the proper insulation of all sub-ambient surfaces that must be done (the pipes will sweat, dripping water on sensitive electronics).

Alternately a new breed of cooling system is being developed inserting a pump into the thermo siphon loop. This adds another degree of flexibility for the design engineer as the heat can now be effectively transported away from the heat source and either reclaimed or dissipated to ambient. Junction temperature can be tuned by adjusting the system pressure; higher pressure equals higher fluid saturation temperatures. This allows for smaller condensers, smaller fans and/or the effective dissipation of heat in a high ambient environment. These systems are in essence the next generation liquid cooling paradigm as they are approximately 10 times more efficient than single phase water. Since the system uses a dielectric as the heat transport media, leaks do not cause a catastrophic failure of the electric system.

This type of cooling is seen as a more extreme way to cool components, since the units are relatively expensive compared to the average desktop. They also generate a significant amount of noise, since they are essentially refrigerators, however the compressor choice and air cooling system is the main determinant of this, allowing for flexibility for noise reduction based on the parts chosen.

Liquid nitrogen

Liquid nitrogen may be used to cool an overclocked PC.

As liquid nitrogen evaporates at -196 °C, far below the freezing point of water, it is valuable as an extreme coolant for short overclocking sessions.

In a typical installation of liquid nitrogen cooling, a copper or aluminum pipe is mounted on top of the processor or graphics card. After being heavily insulated against condensation, the liquid nitrogen is poured into the pipe, resulting in temperatures well below -100C.

By welding an open pipe onto a heat sink, and insulating the pipe, it is possible to cool the processor either with liquid nitrogen, which has a temperature below −196°C, or dry ice. However, after the nitrogen evaporates, it has to be refilled. In the realm of personal computers, this method of cooling is seldom used in other contexts than overclocking trial-runs and record-setting attempts, as the CPU will usually expire within a relatively short period of time due to temperature stress caused by changes in internal temperature.

Liquid helium

Liquid helium, colder than liquid nitrogen, has also been used for cooling. Liquid helium evaporates at -269 °C, and temperatures ranging from -230 to -240 °C have been measured from the heatsink.

Soft cooling

Softcooling is the practice of utilizing software to take advantage of CPU power saving technologies to minimize energy use. This is done using halt instructions to turn off or put in standby state CPU subparts that aren’t being used or by underclocking the CPU.

Undervolting

Undervolting is the practice of running the CPU or any other component with voltages below the device specifications. An undervolted component draws less power and thus produces less heat. However, this generally will make a processor unstable as it no longer has the voltage necessary to carry out instructions error free. As such, in most cases undervolting is accompanied by an underclocking of the processor itself. Keeping the speed/voltage ratio allows a system to be undervolted while maintaining stability. This technique is generally employed by those seeking low-noise systems, as less cooling is needed because of the reduction of heat production.

“wikepidia.org “

Link back-Wiki Article

A video card, also known as a graphics accelerator card, display adapter, or graphics card,
is a hardware component whose function is to generate and output images
to a display.

Some video cards offer added functions, such as video capture, TV
tuner adapter, MPEG-2 and MPEG-4 decoding, FireWire, mouse, light pen,
and joystick connectors, or even the ability to connect multiple
monitors.

A common misconception regarding video cards is that they are
strictly used for video games. Video cards instead have a much broader
range of capability. Being specialized for video, output video cards
improve what a computer monitor displays. As well, they play a very
important role for graphic designers and 3D animators, who tend to
require optimum displays for their work as well as faster rendering in
order to efficiently tone up their work.

Two ATI Graphics Cards 

Video cards are not used exclusively in IBM type PCs; they have been
used in devices such as Commodore Amiga (connected by the slots Zorro
II and Zorro III), Apple II, Apple Macintosh, Atari Mega ST/TT
(attached to the MegaBus or VME interface), Spectravideo SVI-328, MSX,
and in video game consoles. (Wikipedia.com)

Components

THE GPU

A GPU is a dedicated graphics microprocessor optimized for floating point calculations which are fundamental to 3D graphics rendering. The main attributes of the GPU are the core clock rate, which typically ranges from 250 MHz to 850 MHz, and the number of pipelines (vertex and fragment shaders), which translate a 3D image characterized by vertices and lines into a 2D image formed by pixels.

Video Bios

 The video BIOS or firmware
contains the basic program that governs the video card’s operations and
provides the instructions that allow the computer and software to
interface with the card. It may contain information on the memory
timing, operating speeds and voltages of the graphics processor and RAM
and other information. It is sometimes possible to change the BIOS
(e.g., to enable factory-locked settings for higher performance)
although this is typically only done by video card overclockers, and
has the potential to irreversibly damage the card.

NVidia Graphics Card

Video Memory

If the video card is integrated in the motherboard, it may use the computer RAM
(lower throughput). If it is not integrated, the video card will have
its own video memory, called Video RAM. The memory capacity of most
modern video cards range from 128 MB to 4.0 GB.
Since video memory needs to be accessed by the GPU and the display
circuitry, it often uses special high speed or multi-port memory, such
as

VRAM, WRAM, SGRAM, etc. Around 2003, the video memory was typically based on DDR technology. During and after that year, manufacturers moved towards DDR2, GDDR3 and GDDR4
even GDDR5 utilized most notably by the ATI Radeon HD 4870. The memory
clock rate in modern cards are generally between 400 MHz and 3.8 GHz.

Outputs

The most common connection systems between the video card and the computer display are:

Video Graphics Array (VGA) (DB-15)	Analog-based standard adopted in the late 1980s designed for CRT displays, also called VGA connector. Some problems of this standard are electrical noise, image distortion and sampling error evaluating pixels.
Digital Visual Interface (DVI)	Digital-based standard designed for displays such as flat-panel displays (LCDs, plasma screens, wide High-definition televisionnative resolution. displays) and video projectors. It avoids image distortion and electrical noise, corresponding each pixel from the computer to a display pixel, using its
Video In Video Out (VIVO) for S-Video, Composite video and Component video	Included to allow the connection with televisions, DVD players, video recorders and video game consoles. They often come in two 9-pin Mini-DIN connector variations, and the VIVO splitter cable generally comes with either 4 connectors (S-Video in and out + composite video in and out) or 6 connectors (S-Video in and out + component PB out + component PR out + component Y out (also composite out) + composite in).

9-pin VIVO for S-Video (TV-out), DVI for HDTV and DB-15 for VGA outputs.

 Video Cards also have the ability to connect to each other to load frames faster.(more info in separate blogs)

With ATI it is called Crossfire

 And with NVidia It is called SLI Mode

RAM, the abbreviation for “Random Access Memory” A type of volatile computer storage. RAM today, takes the form of integrated circuits that allow any stored data to be accessed in any order (ie at random) Random refers to the fact that any piece of data can be returned in constant time (constant time: refers to the computation time of a problem when the time needed to solve that problem does not depend on the size of the data it is given as input.) regardless of its physical location or if it is related to the data before it.

Unlike storage mechanisms such as tapes, optical disks and magnetic disks, which rely on the movement of the storage medium or the reading head RAM is much faster.  In contrast to RAM, in these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.

RAM is a volatile type of memory storage, which means that when power is cut off to the device or devices the memory is lost.

 Heat Sinks

A heat sink (or heatsink) is an environment or object that absorbs and dissipates heat from another object using thermal contact (either direct or radiant).

Heat sinks function by efficiently transferring thermal energy (”heat”) from an object at a relatively high temperature to a second object at a lower temperature with a much greater heat capacity. This rapid transfer of thermal energy quickly brings the first object into thermal equilibrium with the second, lowering the temperature of the first object, fulfilling the heat sink’s role as a cooling device. Efficient function of a heat sink relies on rapid transfer of thermal energy from the first object to the heat sink, and the heat sink to the second object.

The most common design of a heat sink is a metal device with many fins. The high thermal conductivity of the metal combined with its large surface area due to the fins result in the rapid transfer of thermal energy to the surrounding, cooler, air. This cools the heat sink and whatever it is in direct thermal contact with. Use of fluids (for example coolants in refrigeration) and thermal interface material (in cooling electronic devices) ensures good transfer of thermal energy to the heat sink. Similarly a fan may improve the transfer of thermal energy from the heat sink to the air by moving cooler air between the fins

.

Computer Heat sinks can be cooled by either  free convection, forced convection or liquid cooled. Free convection Is when your heatsink dose not have a fan or any forced air movement . Forced convection is using forced air flow to cool the heatink fins quicker. Liquid cooled is using some sort of liquid to cool the heatsink then the liquid is cooled by a radiator of sorts.

Many new heatsinks use what is called thermal tubes which are essentially copper tubes going from the contact area of the heatsink and then running through the fins. This increases how much and how fast the heat gets to the fins to be cooled.

 CPU-Abbreviation for central processing unit, and pronounced as separate letters. The CPU is essentially the brains of the computer. Sometimes referred to simply as the central processor but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.

The CPU is an internal component of a computer. Mounted on a slot or socket on the motherboard  the CPU dose all the calculations for the computer, runs programs, games, and anything else on your PC.

 CPU core 200x zoom microscope

A CPU consists of many metallic connectors attached to pins on the underside (generally made of gold for conductivity) and a network of microscopic transistors and circuits inside it.  The CPU is housed inside what is called the micro-processor, which since the 1970’s has takes over most other kinds of CPU’s.

The fundamental operation of a CPU is to execute a sequence of instructions called a program. The program is represented by a series of numbers that are kept in some kind of computer memory. There are four steps that nearly all  CPUs use in their operation in order: fetch, decode, execute, and writeback.

The first step fetch involves receiving an instruction. After an instruction is fetched, the PC is incremented by the length of the instruction word in terms of memory units^. Often the instruction to be fetched must be retrieved from relatively slow memory, causing the CPU to stall while waiting for the instruction to be returned. This issue is largely addressed in modern processors by caches and pipeline architectures.

The second step decode is where the instruction is broken up in pieces and sent off to different parts of the CPU for execution.

After the fetch and decode steps, the execute step is performed. During this step, various portions of the CPU are connected so they can perform the desired operation.

The final step writeback simply writes back the information to some form of memory.

CPU’s have a set “clock rate” or cycles per second, which is in turn measured in hertz. And has a major deciding factor on the speed of your computer. Depending on the Cache memory of the processor, how many cores (single, double, tripple, or quad )

A 1.0Ghz processor with exact same computer and CPU specs as a 2.0 Ghzprocessor will run exactly 1/2 as fast as the other. Now if you put a larger Cache on two identacle processors running at 2.0Ghz the one with the higher cache memory will perform better than the other one because it can access the memory quicker.

CPU’s produce a massive amount of waste heat energy. Enough to fry the processor in several seconds without cooling. So that’s where the use of Heatsinks   and Fans come’s in.

Hard disk, data and restore data

There are very few people who have seen a hard disk. Unlike the floppy disk drive are so delicate that must be constantly in a protective aluminum.

Everything you see is a box of metal with some circuits. There is no easy way to access the box to see the disk: open the disc means the contamination.

The units were opened only in clean rooms or rooms where workers wear clothes surgeon and the air is not filtered to contain dust particles. Some discs are included in removable cartridges that are inserted into units, but most are not removable.

IBM invented the disk drive is not removable small and has called Winchester (apparently, because the number of coincided with the model number of a popular Winchester rifle).

Runs, sectors and heads of the hard disk.

Despite all this impressive armour, a hard disk is not very different from a floppy. The data are recorded in written form of magnetic flux in a circle around the ring central disk.

Each of concentric circles form a track and each track is divided into an equal number of segments called sectors. The head read / write moves dall’anello external disk toward the center, stopping above the track which contains the information required by the computer.

Once in the right position, the head expects that the industry is correct to below it, then law or write data in the field. C

Hard Drive, CDs, DVDs, diskettes.

Hard disks are different from other storage media for the density with which data are recorded on the surface of the disk, and the speed with which they operate.

Unlike other media, the hard disk can store up to ten times more data on each track. Because of this density of data is necessary to head a head of read / write very small and very close to the surface of the disk.

Any flexibility of hard disk would jump and beat head read / write. For this reason the disc is made of a hard surface and rigid using slabs of aluminum coated with magnetic material.

The dishes on the hard disk.

In order to improve the capacity most of the hard drive contains two or more disks. The discs, which are commonly called plates, are mounted around an axis called “spindles.” All dishes rotate at the same time.

The engine’s moving plates can be incorporated in the “spindles”, or it may be placed below the “spindle”. Both sides of the plate contain data.

Since it would be impractical for a head reading / writing work for all sides of the dishes, each side of the pot has its head. The heads are grouped in a frame-shaped comb that moves them all at once. The accuracy of this mechanism is impressive. Food and heads must match exactly in every position of every track, being all head to a hundred-thousandth of an inch of the surface of the pot. This geometry both states remains even when the heads are in motion, and asserts back along the surface of dishes, which rotate at high speed. Truly high-tech.

The heads may be close to flat, without touching, because actually fly on the surface because of air flow created by the rotation of the disc. The head rose slowly when the drive begins to move and land without problems when you cut off the flow of current and dishes and they reduce their speed to stop. When the appliance is not working, heads resting on the surface of the disk.

The disk drives are connected to the IDE port on the motherboard, so that when the data are read from the surface of the disc they pass by the heads circuits controller. As we shall see later, not all drive need a controller that acts as an intermediary between the unit and the computer.

The data sent from the surface of the disk controller reach the buffer, a small area of which function as temporary storage for data. Once transferred data in the buffer, the controller sends a signal to the microprocessor to begin the transfer of data to memory chips.

Hard disk UDMA

The data are transferred using one of two following techniques: first in the first computer on the market was the chip to do the work, but currently is used direct memory access (DMA Direct Memory Access).

The DMA has a special chip that moves data directly from the memory controller in a single step, rather than implement the two-step process that requires the transfer to the first microprocessor and then to memory.

Then the data can be found in system memory, in areas that were reserved for the “buffer”. The number of “buffers” and its size is configurable depending on the operating system and application requirements.

To write data, the whole process is reversed. The application tells the system where the data in memory. The system moves to “buffer” and initiates the DMA for the transfer to the disk controller. Then the disk driver starts to write.