How Important is Processor Speed?by John Papiewski
A computer's processor speed strongly affects its overall performance. The speed of a processor in a contemporary computer is about four million times faster than the earliest chips from the 1970s. A faster processor performs simple tasks more quickly than a slow one and it makes sophisticated applications quick enough to be practical. The processor itself is not the only factor involved in a computer's performance however, memory and hard drive speed also come into play.
In the computer, a master timing circuit called the "clock" drives the processor. The first microprocessor, the Intel 4004, had a clock speed of 740kHz, whereas modern examples run at about 3GHz. Although the clock frequency sets the processor speed, you cannot increase the frequency indefinitely; at some point the circuits can't keep up and the processor stops working. Also, higher speeds produce more heat and overheating may become a major problem.
A faster processor can run more sophisticated software and a greater number of tasks overall. For example, high definition games and video players consume significant processor resources; in the 1970s, these programs weren't even possible. Today's window and touchscreen-based programs also depend heavily on fast processors to make the software quick and responsive. A faster processor lets the computer perform multiple tasks competently at the same time, such as downloading a file, playing music, scanning for viruses and spell-checking a document.
The processor is a significant component in a computer, but it is only one among several that impact speed. Other parts, such as the system bus, memory and hard drive play important roles in the computer's performance. The system bus acts as a highway between major components in a computer; it has a maximum speed that is different from the processor's. If the processor is significantly faster than the system bus, the processor must wait for data; this wastes its speed advantage. In the same way, a shortage of RAM makes the processor wait for data from the hard drive. A high-performance computer is the result of all these elements matched to work together efficiently.
In the early 2000s, processors reached a speed limit for practical operation due to problems in keeping the chips cool. To address this, Intel and other chip makers introduced multi-core processors. With this setup, a processor has two or more cores, each of which runs a program independently of the others. A modern software environment such as Microsoft Windows has many programs loaded at the same time, although not all are busy at any given moment. A multi-core processor multiplies system performance by assigning active programs to different cores; this increases the computer's speed without changing the clock rate.