Gigahertz abbreviated GHz, is a unit of frequency. One hertz (Hz) means one cycle per second and 1,000 hertz equals one kilohertz, and 1,000 kilohertz (or a million hertz equals one Mhz) and 1,000 MHz equals 1Ghz (or billion hertz). Hz is named after the German physicist Heinrich Hertz who made considerable contributions to electromagnetism.
One GHz equals 1,000,000,000 (one billion) Hz. Hopefully the table below will make it easier to understand.
|Hertz||1 Hz||0.001 kHz||0.000001 MHz|
|Kilohertz||1,000 Hz||1 kHz||0.001 MHz|
|Megahertz||1,000,000 Hz||1,000 kHz||1 MHz|
|Gigahertz||1,000,000,000 Hz||1,000,000 kHz||1,000 MHz|
For a CPU the GHz refers to the clock speed of the processor. This means that a number of bits (either 8, 16, 32, or 64) are manipulated at one billion cycles per second. Sound fast?
Well that was a 1GHz CPU, (considerably slow now a days, because most computers would have a CPU over 2Ghz which means those bits are now being manipulated at 2,000,000,000 (two billion) cycles per second.
Common examples of GHz are: A Pentium IV CPU (1.6 GHz), running at 1,600,000,000 Hz. Or a 512MB RAM stick running at 233,000,000 Hz.