Glossary CPU (Central Processing Unit) – definition

The CPU (Central Processing Unit) – otherwise known as the processor – is the electronic circuitry that can execute computer programs. Both the miniaturization and standardization of CPUs have increased their presence far beyond the limited applications of dedicated computing machines. Modern microprocessors are appearing in everything from cars to cell phones.

Clock rate is one of the main characteristics of a CPU when it comes to performance. The clock rate is the fundamental rate in cycles per second (measured in hertz, kilohertz, megahertz or gigahertz) for the clock frequency in any synchronous circuit. A single clock cycle (usually shorter than a nanosecond in modern non-embedded microprocessors) switches between a logical zero and a logical one.

With certain CPUs, replacing the crystal with another crystal that oscillates at twice the frequency will generally make the CPU run at twice the performance. This will also make the CPU generate roughly twice the amount of waste heat.

Engineers are working hard to push the boundaries of today’s architectures and are constantly looking for new ways to design CPUs that beat a little faster or use a little less energy per clock. This results in a new, cooler CPU that can run at higher clock speeds.

Scientists are also constantly looking for new designs that allow CPUs to run at the same or lower clock speeds as older CPUs, but that complete more instructions per clock cycle.

Processor clock rates are only useful for providing comparisons between computer chips in the same family and processor generation.

Clock speeds can be very misleading because the amount of work that different computer chips can do in a single cycle varies. Clock speeds should not be used when comparing different computers or different processor families. Instead, some kind of software benchmark should be used.

Smartphones are equipped with more advanced embedded chipsets that can perform many different tasks depending on the programming.

The performance of the CPU which is at the core of the chipset is critical to the everyday user experience and general computing performance of a smartphone. People tend to use the main CPU clock speed to compare the performance of competing end products. But as we’ve shown, processor clock speeds are only useful for providing performance comparisons between computer chips in the same processor family and generation. For all other purposes, it is best to use software benchmarks to determine comparative performance.