DBITsUK Essential Guides
Idiots Guide to Hardware
The Components
The Case – Approx value £30 - £200
You might laugh but the case is very important. This is the main box that holds all the other parts in place and offers protection from the outside world. Without this there would just be a pile of bits under your desk. Seriously though, the case is often the first thing that attracts you to a PC. It’s important to have something that’s pleasing to look at. It will also contain the on/off buttons and access to various sockets that allow you to connect things. Another important function of a case is to keep the PC cool. It does this by having vents and fans to let air in and out.
Cases come in two main styles which are:
1. Tower
The most popular type these days. Everything is mounted vertically so you end up with a tall but narrower structure (like a tower!). Especially well suited to placement under a table.
2. Desktop
In the beginning all PC’s were like this. The exact opposite of a tower system, a desktop case is designed to be placed horizontally on a desk. Great for standing your monitor on!
There is no technical reason why you just can’t lay a Tower on its side or visa versa (I know several people who do this) but it can make access to the CD a bit awkward.
Think of a case like your skeleton and skin:
- Comes in several different colours and sizes
- Some are better looking than others
- Contains all the necessary holes and slots for getting things in and out
- Keeps you cool
- Stops your insides from falling out!
See, I told you it was important!
The Power Supply (often called PSU) – Approx Value £20 - £150
This is where it all starts – the PSU often comes pre fitted into the case although can be changed if needed. It takes the power from the mains cable and pumps it round the PC to power all the components via a network of cables. It’s is very much like the human heart pumping blood through the veins to all the organs. A good power supply is essential for a good system (as is a good heart!)
- Pumps power around the system
- Works best if not overloaded
The Motherboard (sometimes called a system board) - Approx value £30 - £100
The motherboard is a major component. It is a large square circuit board that occupies a large surface area inside your PC and is firmly fixed to the inside of the case. Its primary function is to hold all the other parts in place and organise and pass information between them. Without this absolutely nothing would be able to work or communicate. Without question the hardest part of a computer to replace, although remarkably reliable these days!
Like the muscular and nervous system in the human body:
- Holds everything together
- Allows all the parts to talk to each other
- Makes sure all the information gets to the right place
- A bugger to repair!
The CPU, often called a Processor – Approx value £50 - £800!
The brain inside the box! This is the daddy of components and the centre of all operations inside the PC. Its primary function is number crunching and making sense of all the information which is thrown at it by the motherboard. The more efficient your CPU, the faster your PC will work. The CPU is the part of your brain that really hurts when you do hard arithmetic (or simple arithmetic in my case!). Unlike a real brain the CPU can be removed and often upgraded - If only this was possible in real l
ife!
There are two main names in the CPU business, Intel and AMD. There is an ongoing battle between the two for supremacy but are both great manufacturers. The speed of a CPU is always displayed as a GHz number e.g. 3.0 GHz. Up until a few years ago it was simple – the more GHz, the faster the CPU (makes sense). Unfortunately things are not so clear cut these days as due to huge advancements in processing efficiency (rather than raw speed) it means that it’s now possible to make a fast CPU with lower GHz. It’s very much like the tortoise and the hare principle. If you don’t know the story of the tortoise and the hare then look on the internet and you’ll see what I mean!
In order to confuse things further you can now get CPUs that have two brains joined together. This is commonly referred to as ‘dual core’ technology. Imagine how much more you could do with two brains! This trend is set to continue and it won’t be long before we have four or even eight ‘brains’ inside our computer.
A by-product of all this hard working is heat - and lots of it! (Imagine how much you would sweat if you had to do binary sums all day long!). Because of this, all CPU’s have a fan to keep them cool. This works with the fans and vents in the case to stop everything cooking.
A CPU is like a brain:
- Makes sense of all the information from the nervous system (motherboard)
- Does all the hard sums
- Gets hot and sweaty
The RAM often referred to as ‘memory’ – Approx value depends on size £20 - £200
RAM (stands for Random Access Memory) is effectively working space for the CPU and other components. It’s like having a notepad where you can jot down useful short term information that might assist you in your current task. RAM is supplied in modules or sticks which are about the size of a 15cm ruler. They are put into slots on the motherboard and come in different capacities measured in MB (megabytes). 512MB and above is quite common. Having more RAM is like having a bigger notepad – you can make even more notes and speed things up further. The more complex the task then the more notes need to be made which is why things like video work benefit from a lot of memory. As a general rule more is better. Quality RAM is essential for the smooth running of the system, a shortage or failure in this area means the CPU can’t do it’s job and your PC will crash (either temporarily or permanently). Thankfully it’s quite easy to replace if a fault occurs and motherboards usually have several RAM slots for adding more modules at a later date.
The downside of RAM is that it can’t keep information for a long time – in fact as soon the information is no longer needed it is wiped permanently and the free space made available for the next task. When you shut down your PC the whole lot of RAM is wiped forever.
It’s like the brains short term memory (which explains why I struggle to remember what I had to eat yesterday!)
- It’s very fast
- It remembers useful stuff for speeding up tasks
- Acts as a general information store for other components
- Suffers permanent amnesia when you pull the plug
Graphics Card (often call Video Card or Video Adaptor) - Approx Value £20 to £400
This is an incredibly powerful and often underrated piece of equipment. Its sole purpose in life is to control what you see on the screen and make it look as nice as possible. In the old days this was considered a fairly mundane task and the CPU was left to do the job. As computer games became more advanced, the poor old processor was stretched to the limit handling all the visuals as well as the processing, and there became a need for a dedicated graphics chip.
Several years on and now graphics cards cost more than a CPU and are capable of giving us Hollywood style graphics and effects while leaving the CPU alone to handle more important stuff. They are fairly large (about the size of a large paperback book) and slot into the motherboard. Most have some built in RAM which means they don’t have to use the main system RAM.
A powerful graphics card really comes into its own if you are into playing the latest and greatest games. All you solitaire and Maj Jong lovers need not panic just yet but there is no doubt that a fast CPU and graphics card is a formidable combination. Big names in this field are NVIDIA and ATI
Think of it as having a separate brain that you can use to draw the Mona Lisa in extreme detail while your main one is doing Sudoku and you get the idea!
Hard Disk Drive (often just called hard drive or hard disk) Approx value dependent on size £30 - £150
The hard drive is where information can be stored permanently. It’s about the size of a small paperback (but surprisingly heavy) and connects to the motherboard by a long cable which means it can be fitted in a convenient position inside the case. A hard drive will store anything you throw at it – music, letters, videos, computer games, pictures…the list goes on! It’s the computer equivalent of a massive filing cabinet.
Best of all, anything you put on there will stay put until you delete it. They come in different sizes measured in GB (Gigabytes). To give you some idea, 1GB will hold 250 music tracks, 100s of pictures or 1000s of emails. It’s not uncommon to see drives of 250GB or larger – that’s 62,000 songs!! The downside of all this is that it operates considerably slower than RAM (the other kind of storage in your PC) but it’s still quick enough!
A Hard drive is like your long term memory but even better as it won’t forget your anniversary or what you bought everyone for Christmas last year!
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