What Is a CPU?
CPU stands for Central Processing Unit. It is the term many people give to the processor in their computer. There are many companies that manufacture CPUs or processors, including Intel, AMD, Motorola and Cyrix. They are packaged under names like Pentium, K6-2 or PowerPC.
The CPU, or processor, is the brains in your computer. It processes data, controls the flow of traffic on the buses, and controls what hardware in your system acts on what type of data, and when.
Clock Speed and Performance
A processor is given a speed rating in MHz, or millions of cycles per second. Perhaps you have heard people talk about their 300MHz Pentium II or their 600MHz Athlon. A faster clock speed is NOT the only thing that affects a specific processor’s performance. A 600MHz Athlon is NOT necessarily twice as fast as a 300MHz Pentium II. There are other issues, like instruction sets and cache amount and speed, to deal with. For example, every processor is coded with an instruction set by the manufacturer. These instruction sets tell the processor what to do. Different manufacturers put more emphasis on some things than others, so while that Athlon may be twice as fast on some tasks, it may be three times as fast on others, or considerably slower, depending on what you are doing.