Mr C Johnston ICT Teacher BTEC IT Unit 02 - Lesson 02 Inside Computers #1 – Motherboards, CPUs, PSUs and Cooling

Session Objectives Understand the role of motherboards, CPUs, PSUs and cooling within a PC, Be able to describe the different features of motherboards, CPUs, PSUs and cooling so you can recommend them to others for specific tasks,

The Motherboard The motherboard or “pc main board” connects all the bits of a computer together, It supplies power to, and allows data to flow between all components, There are a series of different slots which cables, and cards fit into, It is important when building a PC that all parts are compatible with the motherboard else the machine will not work.

Motherboard Features System BUS (data, power, control, address) I/O BUS (connects storage devices to motherboard) Front Side Bus (connects processor to the north bridge) Chipset (north bridge, south bridge) Processor slot / socket RAM slots Expansion Slots PCI (peripheral component interconnect), AGP (accelerated graphics port), PCIe (pci express) BIOS (Basic Input Output System) chip Battery FDD, IDE (integrated drive electronics), SATA (serial advanced technology attachment) interfaces Integrated Motherboard Port – USB (1/2/3) / Serial / PS2 / Parallel ports Power socket Optional OnBoard features – Sound, Modem, GRX, Network Point

Conceptual Layout

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Extra Task In your own words explain the function of the motherboard in a typical modern personal computer. The function means what its main job is – include a diagram perhaps showing its main features. Remember explain means to give a detailed account of something with reasons – include how it works, and why its required.

The Processor The processor or CPU is the brain of a computer and performs calculations to enable the computer to function, Its main job is to: Request information from devices, Modify / Create new information, Sending information back to devices. Processors are measure in Hertz (Hz) - number of calculations they can perform per second, Processors attach to a motherboard by being inserted into a socket or slot, In general the faster the processor the better the machine but certain other factors need to be taken into consideration – speed of motherboards bus, amount of RAM, rotation speed of storage drives and type of other cards attached.

The Processor Rivals The two main manufacturers for processors are Intel and AMD, Much debate (similar to Coke and Pepsi) who is better but essentially its down to personal preference and what you want your computer to do, AMD went down the 64bit road, More data can travel around the bus Can use more than 4gb of RAM within your system Have multi core versions or processors Intel first to have several cores, Effectively multiple processors in same case Many of their processors now also offer 64bit technology Which ever you choose need to ensure your motherboard has the correct type of socket or slot for the processor, as different processors require different sockets.

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Current Processors - Intel Intel's latest range of processor are the i3, i5 and flagship i7 range, These mainly have either two or four processing areas and can essentially do multiple calculations (tasks) at the same time, They come in a range of different speeds to suit different budgets and uses; Older core duo processors are still available.

Current Processors - AMD AMD produce a range of processors from high end to budget, AMD Sempron processors are for the budget market whilst Athlon (and its varients) have been around for years and appear in typical home machines, Phemon processors are AMDs high end processors and will be dearer, Most types are offered with different speeds, cores and in 64bit.

Extra Task In your own words explain the function of the processor in a typical modern personal computer. The function means what its main job is – include a description perhaps to explain its main features. Remember explain means to give a detailed account of something with reasons – include how it works, and why its required.

Power Supply Unit (PSU) The Power Supply Unit (PSU) is responsible for supplying power to the various components within the computer, PSUs can either be internal or external, A PSU is a step down transformer converting 230V AC into a lower voltage – in a desktop computer its 12v / 5v DC, There are various cables with different connectors coming out of a PSU – the different connectors are for different devices, PSUs are used all over the world and sometimes there is a voltage selector on the back – its important that this is always set to 230v otherwise BANG!!!

PSU Connector Types 4 pin peripheral power cable -HDD, Optical Drives Floppy drive power cable -Floppy disk drives SATA power cable -SATA devices including HDD, Optical Drives 20 pin ATX main power cable -Motherboards 24 pin ATX main power cable -Motherboards 20+4 pin ATX main power cable -Can be used as either 20 or 24 pin supply 4 pin ATX +12 volt power cable -Supplies motherboards with 12v 8 pin ATX +12 volt power cable -Supplies motherboards with 12v 4+4 pin +12 volt power cable -Can be used as either 4 or 8 pin supply 6 pin PCI Express power cable -Supplies power to PCIe cards 8 pin PCI Express power cable -Supplies higher power to PCIe cards 6+2 pin PCI Express power cable -Can be used as either 6 or 8 pin supply For more explanation visit

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Extra Task In your own words explain the function of the PSU in a typical modern personal computer. The function means what its main job is – include a diagram perhaps showing typical connectors. Remember explain means to give a detailed account of something with reasons – include how it works, and why its required.

Cooling Processors work very hard and get extremely hot, It is important that they are adequately ventilated with a quality heat sink and fan, A heat sink is a metal object that radiates heat array from heat computer chips, A fan is used to suck the heat away from hot computer chips, Ducting may be used to channel to heat out of the computer case, Modern cooling systems include…… Never pick up or try to remove a processor from a motherboard without letting it cool first – you will get burnt.

Cooling Processors work very hard and get extremely hot, It is important that they are adequately ventilated with a quality heat sink and fan, When purchasing a heat sink they often are recommended for a type of processor and speed – using one for a lower spec processor could cause it to blow, Never pick up or try to remove a processor from a motherboard without letting it cool first – you will get burnt.

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Extra Task In your own words explain the function of the cooling system in a typical modern personal computer. The function means what its main job is – include a description and maybe even diagrams showing the different types of cooling system. Remember explain means to give a detailed account of something with reasons – include how it works, and why its required.