ND Unit 02Computer Hardware Internal components
Session Objectives This session looks at what is inside the system unit and what options you may have when purchasing a new system.1. You will learn to recognise these components2. You will learn what these components do3. You will learn where these components go inside the system unit.
System unit componentsWe will look at the following system unit components:Processor (CPU)Fan and Heat SinkMotherboardBIOSPower SupplyHard disk drive – SATA, IDE,EIDE,master/slavePorts – USB, parallel, serialInternal Memory – RAM, ROM, CacheSpecialised cards Network Interface Card (NIC) Graphics Card
The Central Processing Unit (CPU)The CPU is what truly defines a computerIt is the brain of the system & controls everythingIt processes program instructions & performscalculationsSpeed is measured in GHz – the higher the number,the faster the processor works
Fan and Heat Sink or coolingHeat sink conducts heat away from CPUFins on heat sink warms air around itFan moves warm air away from heat sinkcooling the CPU
The MotherboardHouses all the essential partsConnects the parts with busesAlso, connections between the PC and peripheralsgo through it
BIOS Basic Input Output SystemAccessed by pressing Esc, Del, F2 etc.(depending on BIOS make/type)usually on the ROM chip on Motherboardchecks the HW configurationhandles the input and output of the PC.
Power SupplyConverts Mains a/c (alternating current)into d/c 5V or 12v (direct current)Has a fan to stop overheatingPower(on/off)switch connected to front PCOn/Off switch sometimes way to reset PC
Hard Disk – storagePrograms and data are stored permanently on harddisksHard disks are ‘Non-Volatile’ – nothing is lost whenthe power is turned offHard disks are usually measured in Gigabytes
RAM (Random Access Memory)Programs are swapped into RAM for runningRAM is ‘Volatile’ – it loses data when the power is offRAM is measured in bytes (more likely Gigabytes)To preserve data /program instructions for later use,they have to be stored in ROM or on a Hard Disk
ROM – Read Only MemoryNon-volatile - Stores data/settings whenpower offneeded for when you turn onHolds Hardware configuration, eg HardDrive BIOS settings, date and time etc
Cache MemoryLevel 1 – Extremely fast memoryLevel 2 - Very fast memoryL1 & L2 cache make the CPU moreefficient by reducing the waiting time ofthe CPU when it communicates with RAM
PortsPorts provide the link between peripheral and the CPU Parallel – transfers 1 byte (8 bits at a time) Serial – transfers 1 bit at a time USB – (Universal Serial Bus) – A higher speed serial connection ……………………………………… ………………………………………
Network Interface Card (NIC)Allows connection to a networkThe type of NIC will vary with the topology and mediatype in useMany types exists. E.G. UTP NICS, Wireless, FibreOptic, On board, external (plugged in via USB port)
Graphics CardThis generates and outputs images to a displayMany offer added functions such as acceleratedrendering of 3D scenes and 2D graphicsHigh specification cards contain their own dedicatedRAM and processor (sometimes heat sink & fan too)