Overclocking

Overclocking is the process of forcing a computer component to run at a higher clock rate than it was designed for or was designated by the manufacturer.
Overclocking is usually practiced by PC enthusiasts in order to increase the performance of their computers. Some hardware enthusiasts purchase low-end computer components which they then overclock to higher speeds, while others overclock high-end components to attain levels of performance beyond original specifications.
Users who overclock their components mainly focus their efforts on processors, video cards, motherboard chipsets, and Random Access Memory (RAM).(en.wikipedia.org/wiki/Overclocking)