So I was talking to my friend yesterday and he said I should come over and take a look at his CPU because it was getting slow. I was like "CPU? How do you know?" and that is when I understood he meant the WHOLE computer. A CPU is a part of the computer. When we say computer, we usually mean monitor, keyboard, mouse and tower. Here I will explain what are the components of the tower, what drives the whole thing.
Also, the next time you walk into a big box store to buy a pre-assembled system, and you read the little sticker on the tower or the price tag, you will know what it means. Don't let that seller on commission influence you, know what you want, walk-in and walk-out!
Here are the main components we always find in a computer : a motherboard, a CPU (processor), RAM (memory), some sort of video adapter and a storage medium (usually a HDD, hard drive disk).
Motherboard (board, mobo) : The motherboard is probably the most vital piece of equipement in your system. Usually you cannot choose which one you will have in pre-made systems, yet even know which model. A motherboard is like the nervous system of your body, it connects everything together and information flows through it. Everything is connected to the motherboard. If the motherboard dies, it can take everything else with it (rarely happens, but the danger is there). It (usually) comes with on-board sound, so the sound chip is soldered to the board, and with an on-board NIC (network interface card) to connect to the internet.
CPU (processor) : The CPU (central processing unit) is the brain of the computer. All it does is simple mathematic operations, very, very fast. The speed of the CPU is mesured in Hz (Hertz). It indicates how fast it can refresh itself, everytime the CPU refreshes itself, it can do more mathematical operations, so usually the faster the better. Nowadays the speed reached GHZ (giga-hertz) and is sometimes still mentionned in MHz (mega-hertz) for example, a CPU speed of 2.4 GHz or 2400 MHz. We now see with new CPUs coming out multiple cores. An Intel Core2Duo has 2 cores. To put it simply, 2 CPUs in one (not really, but you get the idea). A quad core has 4 and the newer hexa core have 6. I see sometimes on computer ads "Quad core CPU at 2.4GHz so that is 9.6GHz of power!". Right? No. It means 4 cores can each run up to 2.4GHz each. So what do multiple cores do? Multitasking! One core takes care of your web browser and one core takes care of your iTunes. They do not combine powers, but share the load. Otherwise a single core processor (like old Pentium 4s) has to switch back and forth between what it is doing and considerably slows down the computer. Do I really need 4 cores than? Depends what you are doing with your computer! If you are doing video editing, graphic design, encoding, playing video games, usually yes a 4 core will help. Otherwise, a 2 core will be just fine! Remember, you only need to buy for what you need! To sumerize :
- CPU is the brain
- it does math really fast
- measured in Hertz
- the faster the better (usually)
- cores do not stack up, they help multitasking
RAM (memory) : Oh RAM (randomly accessed memory)! How we neglect you sometimes! But what does RAM do? Imagine you have a kitchen counter and you are about to cook. To start you need to take out and lay in front of you all the ingredients you are going to need. You start cooking and suddenly your son/daughter arrives from school and puts their backpack on the counter. Out of nowhere, your husband/wife shows up and wants to put more things on the counter. Now, if the counter is big enough, there is room for everyone, but if it is full, you need to put some things away and you will always have to go back for them if you want to use them, which would slow you down. RAM works the same way. Everything that happens in the system, all the information, passes through the RAM. You need to make sure you have enough for all the information to be stored. RAM prices have dropped considerably in the last year, so the size is usually not an issue. Like the CPU, RAM speed is mesured in Hz. Ranging from 1333 to 2000+ MHz for the new DDR3 technology. I won't bore you with all the different types of RAM, since the amount is the only thing available usually. For most systems, 4GB (gigabytes) of RAM is more than enough. With prices being low, amount of RAM is rarely an issue. So :
- RAM is like your kitchen counter
- stores information for the system but it is erased everytime the system is turned off
- measured in Hz (speed) and GB (capacity)
- 4 or 6GB are perfect amounts for almost everyone
Video card/graphics card : The graphics card market is always changing, with new and more powerful cards coming out every 6 months. Here you only need buy what you need. For web browsing, emails and word processing, a low, entry level card will do. Want to watch Blu-rays and HD videos? Something mid-range. Gaming? Mid-range to high-range. There are "two types" of graphics card (kinda), discrete and on-board. A discrete card is seperate from the motherboard and is usually more powerful (made by nVidia or AMD) while an on-board is less powerful and you cannot change/upgrade it, but you can add a discrete card down the road if you wish. If it is not specified, always assume it is on-board (attached to the motherboard) and is probably a low-end card. The video card handles the display of information on your monitor. A powerful video card can take some stress off the system because it will calculate some things to free up CPU cycles. But again unless you are doing something intensive for the computer, you will not notice it.
Storage medium : Usually a hard disk drive, here only the space matters. If you need more space, go bigger. If not a small drive will do. Measure in GBs and TBs (1TB = 1000GB).
I hope this helps to clear out some mysteries about computers!
Feel free to email questions and comments to firstname.lastname@example.org