How does a CPU clock work?

clock CPU

The CPU clock works off of a quartz crystal. Quartz — which is silicon dioxide like most sand — is unaffected by most solvents and remains crystalline to hundreds of degrees Fahrenheit. The property that makes it useful is that when compressed or bent, it generates a charge or voltage on its surface. This is called the piezoelectric effect. In the same way, if a voltage is applied, quartz will bend or change its shape very slightly. A quartz crystal is used within the clock. Often, these crystals are made from thin sheets of quartz plated like an integrated circuit and etched chemically to shape. The major difference between good and indifferent time keeping is the initial frequency accuracy and the precision of the angle of cut of the quartz sheet with respect to the crystalline axis. If contaminants are able to reach the crystal, the accuracy can be affected. The electronics of the clock initially amplifies noise at the crystal frequency. This builds or regenerates into oscillation