How Does a CPU Processor Work?

Central Processing Unit

A CPU, or "central processing unit," is an electronic device commonly referred to as a "circuit" that is designed to execute a variety of computer programs and processes. Early versions of the CPU were custom designed to the computer they were placed inside, which often made them capable of doing only what that specific computer was intended to do. Presently, CPUs are mass produced in factories, which means all versions of the same CPU from the same brand will be identical. They are now produced to be able to perform a wide variety of functions.

Programs

No matter how complicated a task you are currently trying to complete on your computer, it is all made possible by the CPU running a series of very simple programs. In this case, the term "program" does not refer to a piece of software (Adobe Photoshop, for example) as is commonly used, but a series of stored instructions. The CPU will perform four steps in executing any program it requires: it will get, or "fetch," the instructions from its memory, decode the instructions into a series of zeroes and ones in order to be able to read them, then execute the instructions will publish, or "writeback," the results of the instructions in its internal memory.

Clock Rate

The speed, or "clock rate," of a CPU is the rate at which it performs the execution of the previously mentioned programs. This is measured in hertz, which are the cycles per second. CPU manufacturers like Intel will charge consumers more money for a CPU with a higher clock rate than one with a lower rate. These rates have changed drastically over a relatively short period of time. In 1995, a 100MHZ processor was considered fast. In 2004, a 3GHZ processor, which is thirty times faster than a 100MHZ processor, was the standard.