The speed of a computer processor, or CPU, is determined by the clock cycle/clock frequency, which is the amount of time between two pulses of an oscillator. The higher number of pulses per second, the faster the computer processor will be able to process information. The clock speed is measured in Hz, typically either megahertz (MHz) or gigahertz (GHz). For example, a 4GHz processor performs 4,000,000,000 clock cycles per second.