Chapter 2

Processor Overview

The Central Processing Unit, Which is often referred to as the "Processor" is the brain of the computer. The chip that performs the majority of calculations and instructions needed to make your computer run. Without this chip, no other function of the PC is possible. The processor is attached to the motherboard (Processor slot).

The computer's speed or clock rate is integral to its overall design. The computers clock rate is the frequency at which it can execute a set of instructions. Computer clock rates are measured in Megahertz (million of clock ticks per second).

There are two types of speeds that should be considered when evaluating the system performance:

Internal clock speed - Is the speed at which the processor can obtain information within itself, like with internal cache and registers. (Pentium III 800 MHz. the 800 MHz is the internal clock speed)

External clock speed - Is the speed at which the CPU communicates with components outside itself.

Some commercially available processors:

Pentium I-IV

1. Celeron

2. Athlon

3. Duron

4. Cyrix C3

5. Itanium (64 bit)

6. Opteron (64 bit)

How to Choose a CPU

When you are choosing one CPU always consider your computing needs when selecting a CPU. If you want to do simple word processing or general computer tasks, go for the budget or low end processors. If you are more into gaming or do CPU intensive work like video editing, go for a mid-range or high-end processor.

The processor you choose determines how fast the system runs, and how long it will provide subjectively adequate performance before you need to replace the processor or the system itself. Buying a processor just fast enough to meet current needs means that you'll have to upgrade in a few months. But processor pricing has a built-in law of diminishing returns. Spending twice as much on a processor doesn't buy twice the performance. In fact, you'll be lucky to get 25% more performance for twice the money. So although it's a mistake to buy too slow a processor, it's also a mistake to buy one that's too fast.