Function of computer hardware components

Computer hardware components include internal system components such as the motherboard and hard drives, peripherals such as printers and cameras and back devices such as USB pen drives. When explaining the function of computer hardware components describe each component individually and try to use an example screenshot to support your answer. Part of explaining is including technical requirements and comparing different components to discuss the differences.

Internal system unit components:
This section discusses internal system unit components and gives basic explanation to help you put your answer together to explain the function of computer hardware components.

A processor is the brains of any computer system. Also known as a CPU or central processing unit it is used to execute instructions that enable the operating system and application software to run on a system. A processor performs arithmetic and logical calculations in the ALU (arithmetic logical unit) and control instructions in the control unit. The processor communicates with storage devices such as the hard drive and RAM to process information used to control the operating system and applications that run on a computer system. Processors are being made smaller and faster all the time and this allows systems to carry out instructions faster and perform better. A processor in a mission critical system used in space or a medical device needs to be very powerful to carry out instructions quickly.

Processors are integrated into a computer system by placing them on the motherboard. A Motherboard is like the body of a computer system it contains a socket to house the processor and links a lot of internal components together such as RAM and graphics cards using communication buses. The have integrated controllers to enable the processor to communicate with storage devices such as HDDs and CD/DVD drives. A motherboard is a printed circuit board (PCB) and links the components using lines drawn on the circuit board. Motherboards contain expansion slots to insert RAM or graphics, sound and network cards to improve system performance. They allow a computer engineer to upgrade the RAM so that a machine runs faster. Motherboards also contain sockets to enable a computer system to communicate with external devices using USB ports, sound jacks and VDU outputs. A motherboard comes in different form factors (this is the shape and size) and you need to check if components are compatible with this form factor before purchasing them. A phone also has a motherboard which is much smaller than that used in a PC obviously. PC motherboards normally require them to be cooled to keep components running at optimal performance. This is done using fans and heat sinks.

BIOS or basic input/output system is firmware (firmware links hardware and software) built into a computer system. The BIOS is used to ensure that a system boots up correctly and all hardware components are configured to work correctly. It contains information about the hardware components connected to the system such as keyboard and mouse and enables applications installed on the system to be controlled by the hardware. The BIOS is stored in non-volatile ROM (read only memory) of a system and is configured to allow that motherboard and all connected components and peripherals to run correctly.

A power supply or PSU (power supply unit) is used to power all of the components in a computer system. The power supply runs from 120 or 240 volts mains supplied and provides 12v, 5v and sometimes 3.3v outputs to power different components. A hard drive needs a power supply to run and the PSU has a specific output connector that can be used to connect to different hard drive types. Standard connectors are ATX – you can find out more by researching the different type of connectors that power supplies have. They normally range from between £20 to £50 in price.

A fan is used in a computer system to suck hot air out of the system to make sure that it does not overheat. Most computer systems will have fans on the casing to suck the hot air out of the system. The fans are connected to the power supply. Most processors also have a fan connected to them to draw the heat away from them and ensure the operate at the best speed possible. You will hear a system that is getting hot become noisy as the fans increase in speed. Heat sinks are also used to keep systems cool. Heat sinks are made from materials that draw heat away such as aluminium and copper. Often a heat sink is placed on top of a processor to draw the heat away from it. A fan will be placed on top of the heat sink to continuously draw out the heat that the processor produces. This heat is then drawn away from the systems by fans placed on the casing. Sometimes water is used to cool systems that are prone to heating up – you can investigate this further to see how water cooling is used in gaming systems as an example.

For a computer system to run it needs a storage system to store information about the operating system and applications. Knowledge of hard drive configuration and controllers is an important skill to have when setting up a system. There are different ways to communication with HDDs (hard disk drives) such as SATA, IDE or EIDE. SATA or Serial ATA (Serial Advanced Technology Attachment) is a serial communications method that communicates over a serial cable. If your motherboard is configured with SATA then you need to buy a SATA compliant HDD. IDE (integrated drive electronics) that has the controller for the hard drive stored on the drive itself. Master/slave configuration is used when installing an additional HDD on your computer system. The master/slave hard drive configuration means that both drives can be controlled using a single cable. The IDE controllers in each HDD talk to each other to say when it is ok for the system to send or receive data to and from the storage device. If the master drive is in use it will send a message to the slave to tell it that. When the master drive is finished communicating with the system it will send a message to say that the communications are complete and the slave can go ahead and perform the required actions. This is normally configured using hardware jumpers to say with is the master and which is the slave drive.

Most computer systems use ports such as USB, parallel and serial to communicate with external devices. A USB (universal serial bus) port allows you to plugin in an external storage device such as a keyboard or mouse to connect to the motherboard and enable the user to control the system. The motherboard comes with a USB controller chip to enable the communication to take place. Parallell ports were initially used for printers and are not as common these days. They are used for devices that need a lot of communication such as a plotter used in sign writing. The have more communication lines than a serial port and therefore can send and receive more data.

In order to explain the function of computer hardware components in full it is important to consider the internal memory components of a computer system. The three main types of internal memory in a computer system are RAM, ROM and cache. RAM or random access memory is memory that linked to a processor on the motherboard. Data can be written to and read from random access memory at roughly the same speed. RAM chips are stored on separate printed circuit boards that can be plugged into a system motherboard. Applications write data to the RAM chips based on current operations. RAM is wiped when a systems shuts down. For example, if a large amount of data is copied on to the clipboard it would be stored in random access memory. If you do not clear the clipboard the information will still be available to paste in an hour or even week’s time but if the system shuts down the information will not be available to paste as the RAM will be cleared. RAM upgrades can increase system performance as more applications can be used at the same time with less impact on system resources. ROM or read only memory contains system information such as the BIOS (although some bios is stored directly on the motherboard itself). Although it is considered read only it can be configured in some sense like setting the BIOS password. ROM also stores information about the operating and other programs stored on the system. ROM does not get wiped when a system reboots. Cache memory is ram that can be accessed much quicker than regular RAM that is slotted into a motherboard on a computer system. Cache is normally stored within the CPU or on a separate cache memory chip located right beside the CPU. Cache has different levels high speed and ultra high speed. L1 or level 1 cache is normally stored on the CPU chip and is the fastest type of cache. Cache memory is used by the processor to carry out instructions more quickly as data can be accessed by the processor quicker due to the proximity of the cache and ultra high speed.

Specialised cards such as network and graphic cards are used to increase the functionality and performance of a computer system. Some motherboards come with integrated graphics meaning that the graphics driver is stored on the motherboard. For better graphical performance a specialised graphics card with increase the performance in terms of outputting a better quality and higher resolution picture from your computer system. Installing a specialised graphics card would be important for someone like a movie editor who wanted to see the full impact of high definition video when editing. A network card can be plugged into an expansion slot to enable a computer system to connect to a network. This can be an internal network or the world wide web. Again some motherboards come with integrated networking capability but installing a specialised NIC (network interface card) will increase performance in terms of connection speed etc.

Peripherals:
Another thing that you need to look at to explain the function of computer hardware components is peripherals such as input and output devices and cabling.

Output devices consists of monitors, printers, plotters or speakers. A monitor sometimes known as a VDU (visual display unit) outputs the signal from the operating system and applications to show the information to the end user. Monitors are improving all the time in terms of picture quality, power consumption and weight to size ratio. Printer and plotters are used to output information designed on a computer system in printed format. Plotters are used by sign writing companies to cut out stick on vinyl. Specialised design software is used to control the cutter on the plotter by outputting a signal.

Input devices such as cameras, scanners, keyboard or mouse are used to input information into a computer system. In the case of a camera it can be connected to a computer system and images uploaded and editing. The images can also be printed out after they have been input from the camera. Scanners are used to input images of documents into digital format on a computer system. A scanner is particularly useful for backing up signed documents for company records. Obviously a keyboard and mouse are the main input devices used to control a computer system to type information and control the cursor on screen.

Cabling is used to connected peripheral to a computer and to connect the computer to a network. Coaxial cables can be used for television and computer data applications and the signal noise is reduced by shielding. Two types of networking cables are optical of fiber optic cable and twisted pair cables. Fiber optic cables are high speed network cables that transmit light pulses through an optical fiber to transfer data at high speed. ISPs (internet service providers) provide high speed internet connections using fiber optic networks. Fiber optic cables are expensive. Standard ethernet cables use twisted pair technology. The twisted wires work in tandem to cancel out any noise loss between them. The interference on one cable is cancelled by the other cable and this is an effective data transmission solution over a network.

Backing storage:
Backing storage is used to back up information stored on a computer system. By performing regular data backups you limit the chances of losing valuable information stored on the system. If you backup regular then a computer system can be restored easily without any data loss. There are many types of backing devices both portable and fixed solutions and the performance of backup is effected by the data transfer rate and storage capacity of the backup storage device.

One form of backing storage is optical media such as compact disks. These can be used for small backup applications as they are limited by size. An example might be to back up website html and image files to a CD. CDs can only be written to once but a CD-RW storage device is a rewritable disk that can be used as a recurring backup. CDs can be purchased in different read/write speeds. A USB or pen drive is a small portable storage device that is made using flash memory. USB pen drives have developed over time and USB 2.0 and 3.0 offer faster read write storage backup that earlier versions. Whilst USB drives started out at very small about 128Mb they can now be purchased in much bigger sizes such as 1Tb. They were initially very expensive but the price has dramatically decreased in the past few years making them a viable backup storage solution for individuals.

A usb stick could be seen as a portable drive as you can take it with you anywhere as it is lightweight and can be connected to most standard computer systems using plug n play technology. Fixed backing storage devices are used where much more storage space is needed to backup your data. A company may have a fixed drive stored on their server to backup up important project information on a daily basis.

Backing storage is mainly affected by two performance factors; data transfer rate and capacity. Data transfer rate is important when you are backing up large amounts of data. If you are backing up a web server on a daily basis or even in real-time you will need to be able to read and write the information very quickly to ensure no data is lost and the amount of data can be transferred as quickly as possible. If the data that needs to be backed up is not that large then the data transfer rate is not as important and a cheaper backup solution could be obtained. The second factor to consider is storage capacity. If you are backing up a server then you need a backup drive with at least the same storage capacity as that on the server. If an IT freelancer backed up projects on an individual basis then they might just use CDs or individual portable pen drives that can be stored on a server also as a secondary backup. The capacity must be considered in advance depending on the type of data that will need to be backed up.

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