How to Compare Processor Performance
When shopping around to upgrade your fleet of business computers, the metric that stands out on labels and in ads is processor -- or CPU -- performance or speed. You should not, however, try to compare performance based on this one number. Processor performance is dependent on a number of factors and can vary depending on the hardware environment and the task being performed.
CPU clock rate, sometimes inaccurately called "speed," is a figure that reports the number of basic calculations, such as adding two numbers together, per second that a single processor core is capable of. The figure is based specifically on the frequency of an oscillator crystal which regulates the processor's speed and temperature. A processor which runs at a higher temperature can run at a higher clock rate. Clock rates are measured in gigahertz, or billions of wave oscillations, per second. Typical processor cores have clock rates of between 1 GHz and 4 GHz. While clock rate is almost always reported as a spec for a machine, rarely does the clock rate alone mean much for a CPU's overall performance, much less a computer's.
Most contemporary CPUs contain between two and eight "cores." Multiple cores allow processors to break tasks up and distribute them for higher performance. Multiplying the number of cores times the clock rate can give you a rough estimate of the processor's maximum performance, but the number would not be totally accurate as some processing has to go into distributing tasks, and some applications make better use than others of multiple cores.
To truly establish a processor's performance, the processor has to be put to work on real-world tasks. Good benchmarking tests exercise processors by collecting information from a number of different hardware environments, each running a specific set of tasks. The results can then be compared to the results of other similar processors. Results of these tests, which represent fairly accurate estimates of processor performance, can be found at sites like Tom's Hardware and CPUBenchmark.
The performance of a CPU is only one of the factors that determines overall computer performance. Disk drive access, network speed, video card performance, amount of memory and memory access speed can all affect system speed and responsiveness. Some combinations of hardware perform better than others as well. Besides looking at the CPU benchmarks and metrics reported by the manufacturer, it's a good idea to read reviews of specific systems to find out how they perform in the real world.
Brian Jung has been writing professionally since 1991. Currently he works as a software developer for University Hospitals in Cleveland, Ohio, where he also contributes reviews and commentary on children's and young adult literature to his own blog, Critique de Mr Chompchomp, and to Guys Lit Wire. Brian holds a Doctor of Philosophy in English from the University of Wisconsin, Milwaukee.