CPU multiplier

From Wikipedia, the free encyclopedia

The CPU multiplier is one way for processors to run much faster than the clock speed of the motherboard or RAM allows. For every tick of the front side bus (FSB) clock, a frequency multiplier causes the CPU to perform x cycles, where x is the multiplier.

For example, if the FSB has a clock speed of 133 MHz and the CPU multiplier is 10x, then the processor would run at 1.33GHz. This means a processor can run much faster without having to increase RAM speeds or motherboard speeds and worry about desynchronizations, or other speed-related issues.

The CPU multiplier is frequently used by PC enthusiasts to overclock a CPU to get somewhat higher performance from it.

One downside of the multiplier is that it only increases CPU speed. In the previous example there is a multiplier of 10x, but RAM still runs at 133 MHz, so the computer can only access memory at 1/10th of the processor speed, 133 MHz, the speed of the FSB. Because of this, many overclockers prefer to have lower multipliers with higher FSBs.