Microprocessor

The most important of the electronic components on the motherboard is the microprocessor. It does the actual thinking inside the computer. The power of a computer—how fast it can accomplish a given job, such as resizing a digital photo—depends on the model of microprocessor inside the computer as well as how fast that microprocessor operates (the speed is measured in the familiar megahertz or gigahertz). The kind of microprocessor also determines what software language it understands. For example, Windows computers and Macintosh computers use microprocessors from different families that understand different software languages.

As fits its role, the microprocessor usually is the largest single integrated circuit in a computer. It makes more connections, so it has the biggest socket and usually holds the dominant position on the main circuit board. It is the centerpiece of every computer. In fact, the microprocessor is the most complicated device yet devised by human beings, so complex that earlier designs couldn't fit all the silicon microcircuitry into a single chip. Many older microprocessors (such as the Pentium II series) were modules that combined several smaller integrated circuit chips into a big assembly that included a main microprocessor, a coprocessor, a cache controller, and cache memory. Today, however, everything for an advanced microprocessor such as the Pentium 4 fits on a single silicon chip about one-inch square.