Overclocking is achieved by manipulating the CPU multiplier (bus/core ratio) and the motherboard’s frontside bus (FSB) clock rate. The clock rate is the number of cycles per second produced by an oscillator or crystal. Clock speed regulates the timing for a synchronous circuit. A single clock rate is generally less than a nanosecond (one billionth of a second) on newer nonembedded microprocessors that toggle between logic 0 and logic 1. The CPU multiplier measures the ratio of the internal CPU clock rate against the external supplied clock. The CPU multiplier is generally changed in the basic input/output system (BIOS) setup.

Overclocking can improve the speed of information being processed, but it can sometimes be harmful to components - especially if they are not upgraded. This is because clock rate is only one feature of the many that influence PC performance. Other factors that affect a PC's performance include:

• The internal layout
  
• The the width of the CPU's bus, which transfers data between internal computer components
  
• The clock rate of the memory chip and frontside bus
• The speed of the disk storage system
• The amount of Level 1 and Level 2 cache

Overclocking can be a complicated process. There are many aspects to consider, such as:

• Voltages
  
• Individual semiconductor clocks
• CPU multipliers
• Thermal loads and tolerances
• Bus dividers
• Cooling techniques
  
• Proper settings and having adequate power to operate at the new clock rate

One method of overclocking a processor is to alter the hardware jumper settings or to increase the speed of the CPU that is located in the system BIOS. Altering the settings might improve overall performance.

Sometimes performance is only improved slightly because most component settings are permanently fixed, such as those of the frontside bus speed, backside bus speed and the memory speed.

The advantages of overclocking are:

• Faster performance for applications and games
  
• A cheaper price for a slower processor overclocked to the speed of a more expensive processor
  

The disadvantages may include:

• Shortened component lifespan
  
• Damage to circuitry
  
• Noisy cooling fans needed for the excess heat
• More frequent hardware crashes with occasional data loss