The speed of a processor is based on its clock speed, which is measured in Gigahertz (GHz) or Megahertz(MHz). One MHz equals 1,000,000 cycles per second and one GHz equals 1,000,000,000 cycles per second. The higher the clock speed, the more tasks the processor can execute per second.
The clock speed of a processor is usually determined by a quartz-crystal circuit. Clock speed is not the only factor that determines the performance of a processor. Other elements like the bus architecture, type of microprocessor and cache memory also play a key role in processor speed. The amount of RAM (Random Access Memory) is also detrimental to CPU performance.