WARNING: I am not liable for any damage done to persons, hardware or software as a direct or indirect result of following this guide. You overclock totally at your own risk!

Overclocking of the processor is the art of increasing the speed setting on the motherboard to force the the processor to run at a higher speed. The speed setting on the motherboard is governed by 2 variables. Clock speed and clock multiplier. By increasing the clock speed to a higher value, the speed of the processor, memory, level 2 cache and in some cases PCI peripherals will increased. It is recommended that you try this, if possible, first. By increasing the clock multiplier, only the processor speed will be increased. If the clock speed is lowered and the clock multiplier is increased to obtain a higher processor speed, in certain cases, there might even be a decrease in speed (the increase in processor speed is not enough to offset the reduction of speed in the memory and level 2 cache). As a rule, always try to increase clock speed first, then followed by clock multiplier and never increase the clock multiplier at the expense of reducing the clock speed. The second rule is to increase the clock speed only in small steps at a time and to monitor the sideeffects caused each time. Note that overclocking should be done when the computer is OFF!

The basic principle of overclocking is to keep the processor cool (temperature is proportional to the chances of the processor failing). Use a large heatsink with a high efficiency fan or a peltier junction. Of all the CPU fans I've tried, I'm most impressed with AAVID. It does a remarkable job of removing heat from the processor and this in turn allows me to overclock to even higher speeds. You might also want to install secondary fans into the casing or even (if you are an overclocking fanatic) remove the casing cover to allow for better ventilation.

If overclocking is sucessful, the computer should operate as normal (but faster!). Should it not be successful, sideeffects and tell tale signs are hanging after a few minutes of use, general protection faults in Windows or even the inability of boot up. On the topic of hanging, be sure to check that the hanging is a result of the overclocking and not a software problem.

Should the system perform unreliably after overclocking, try increasing the potential difference of the processor slightly. A range of voltages from a high 3.5V to a low 2.1V can usually be set on the newer motherboards. Most processors allow for a plus or minus 0.2V. Although increasing the potential difference will increase the reliability of the processor, the heat generated will increase as well, so it is neccessary to find an optimum balance between the potential difference and the heat generated (an increase of heat will reduce reliability).

Motherboards which are able to provide a clean source of power supply for the processor (ie. good voltage regulators) are the most ideal to use for overclocking. These motherboards are usually characterised by large capacitors positioned next to the processor socket.

Do also take note that, to prevent overclocking, Intel has disabled the higher clock multiplier settings on some of its processors (low end Pentium MMX and Pentium 2 processors) by simply not bonding one of the multiplier pins. Although this prevents overclocking by the use of higher multiplier settings, such processors can still be overclocked by increasing the bus speed on the motherboard.

A new development in the art of overclocking is the emergence of the useful utility known as Rain. This programme issues the HLT command to the parts of the processor that are not currently in use, thus switching them off (ie. suspend mode). The result, as expected, is a small but very useful reduction in heat generation of the processor.