What is a CPU ?

CPU: Central Processing Unit
The Central Processing Unit or CPU is the key component of a computer system, which contains the circuitry or microprocessor needed to interpret and execute program instructions . While the CPU has been called the “brain” of the computer, you might think of it as the device that manages how your computer accesses and uses information.
The CPU in our laptops or desktops is small and square, attached to the motherboard CPU socket by a configuration of metal pins. Since CPUs get heat up very quickly when in use, a heat sink and fan help dissipate heat generated by the CPU. This is why setting your laptop on your lap gets a bit warm and you often hear a fan blade sound coming from your laptop.

A CPU has two major components: the arithmetic logic unit and the control unit. The arithmetic logic unit performs the essential addition, subtraction, multiplication, and division arithmetic functions. It also performs the logical functions comparing two data items, such whether one number is larger than another [2]. The control unit manages four essential operations: fetch, decode, execute, and store.
• Fetch: retrieves the program instruction the computer needs to run from the program memory.
• Decode: interprets what the program is telling the computer to execute.
• Execute: performs the requested instruction
• Store: stores the results in the CPU or in RAM
When these four steps have been completed, the CPU moves onto the next instruction and repeats the entire process again, until the program run is finished.
The cycle of these four process steps is referred to as the machine cycle. Now if you consider the number of machine cycles per second, referred to as the clock cycle, the figure is staggering. Contemporary laptops feature 2.5 GHz CPUs, or processors that run the machine cycle 2.5 billion times per second, while a three year old laptop might offer a 2 GHz CPU.
There is more to what powers CPU speed than clock speed, such as parallel processing which as we can see in the Intel Core Duo processor family. Yet machine speed is a key decision factor that buyer use to choose one personal computer over another. So while the CPU may be the brain of the computer, it is also at the heart of purchase decision.
Some latest(as on 26 Jan 2012) CPU's from different manufactures are given in our latest technology section.

enjoy have fun....!!!!

Shantanu

Posted in: Hardware