Mac OS X

Mac OS introduced the graphical user interface to the world. The original Macintosh operating system was released in 1984. By the late 1980s, the Mac’s operating system was the most technologically advanced in personal computing. However, Apple Computer was unable to capitalize on its lead, and Mac OS (as it came to be called after system 7.5) lost market share to Microsoft Windows. Still, Mac OS is widely considered to be the easiest operating system for the beginning computer users. In 1998, Apple was reinvigorated by the return of founder Steve Jobs. A new version of the operating system, called Mac OS X, was released in 2000 and bought Mac OS up to speed with Microsoft Windows.

Microsoft Windows

Microsoft Windows is by far the most popular operating system. Over the years, in has gone through many iterations, and now it is now considered the operating system of PCs worldwide. When you purchase a computer, it comes with an operating system already installed. Microsoft makes agreements with the major computer manufacturers to provide Windows on almost all of the personal computers that are made today. Some manufacturers offer a choice of operating system, but will remain the standard for years to come.

Parallel Processing

Another way to improve CPU performance is with parallel processing, a technique that uses more than ne proceeding running simultaneously, in parallel. The idea is to speed up the execution of a program by dividing the program into multiple fragments that can execute simultaneously, each on its own processor. A program being executed across more than one processor will execute faster than it would by using a single processor.

The System Clock

Within the computer, events happen at a pace controlled by a tiny electronic “drummer” on the motherboard called the system clock. The system clock is an electronic circuit that generates pulses at a rapid rate and synchronizes the computer’s internal activities. These electrical pulses are measured in billions of cycles per second (gigahertz or GHz) and referred to as a processor’s clock speed. Any computer you purchase today will have a clock speed of more than 1Ghz. Thus, a 3-GHz to 4-GHz (overclocked CPU) processor is capable of processing 3 billion cycles to 4 billion cycles respectively in 1 second. In general, the higher the processor’s clock speeds, the faster the computer.

The Operating System

The operating system (OS) is essentially a set of programs designed to work with a specific type of computer, such as PC or a Macintosh. Its most important role lies in coordinating the various functions of the computer’s hardware. The operating system also supports the application software you run. An operating system performs five basic functions. In starts the computer, manages applications, manages memory, and handles messages from input and output devices, and provides the user interfaces (a means communicating with the user). The operating system is most often found in hard disk, although on some small handheld computers it is on the memory chip.