Overclock your PC

Setting the processors speed to run faster than the manufacturers rating on the chip is called overclocking. You can get away with a certain amount of overclocking on Intel, AMD, and other processors. So, a chip rated 3GHz might in fact run at 3.5GHz or more but instead being down-rated allows for a greater margin of reliability. By overclocking, you are using this margin and running the chip closer to its true maximum speed. I don’t normally recommend overclocking for a novice, but if you are comfortable playing with your system settings, and you can afford and are capable of dealing with potential consequences, overclocking might enable you to get another 10%–20% or more performance from your system.
Overclocking is usually applied to the processor, but it can also be applied to other components in the system, including memory, video cards, bus speeds, and more.
When chips run faster, they run hotter, so cooling upgrades and modifications usually go hand-in hand with overclocking. Systems that run cool tend to be more stable and more reliable, so even if you don’t overclock your system, ensuring that it runs cool is essential for trouble-free operation. Many systems are not properly designed or configured for optimal cooling even at their standard speeds, much less when overclocked.
Modern systems allow overclocking without replacing any parts by virtue of programmable timer chips and simple and easy-to-change BIOS Setup options. Some processors, such as Intel Extreme Edition and AMD Black Edition processors, are especially suited to overclocking because they feature unlocked core multipliers. However, some overclocking is possible with almost any processor.
A typical PC has at least two crystals on the motherboard: The main crystal controls the speed of the motherboard and motherboard circuitry, and the other controls the real-time clock (RTC). The main crystal is always 14.3MHz , and the RTC crystal is always 32.7KHz. A special chip called a frequency timing generator (FTG) or frequency synthesizer is used in conjunction with the crystal to derive the actual speeds of the system. A separate 32.768KHz crystal to count time independent from the speed of the system. This crystal is used on all modern motherboards as well.The crystal and frequency synthesizer chip are usually situated near the processor and main chipset component of the motherboard. Most of these chips are programmable and adjustable, so they can change their frequency outputs via software, which results in the system running at different speeds. Because all CPUs are based on the speed of the CPU bus, when you change the CPU bus speed generated by the frequency synthesizer chip, you can change the speed of your processor. Because the PCI, AGP, and memory buses are often synchronized with the speed of the processor bus, when you change the processor bus speed by a given percentage, you also change the speed of those other buses by the same percentage. The software to accomplish this is built into the BIOS Setup menus of most modern motherboards.
The modern motherboards can read the CPU and memory components to determine their proper speed, timing, and voltage settings. Originally, these settings were controlled by jumpers and switches, but in most modern boards you can enter the BIOS Setup to change these settings to manual and then alter the speed of the system. Such alterations can make the system unstable, so most systems are designed to boot into the BIOS Setup at a default low speed. This makes overclocking as simple as changing a few menu options and then rebooting to test the selections you’ve made.
The concept for overclocking is simple: Change the settings to increase the speed of the processor, memory, buses, and so on, until the system becomes unstable. Then you can go back in and reduce the settings until the system is stable again. In this manner, you find the maximum sustainable speed for a system. Because each processor is different, even ones with the same ratings can end up allowing different maximum stable speeds.

Bus Speeds and Multipliers

Modern processors run as a multiple of the motherboard speed, and this selected multiple is usually locked within the processor , all you can do to change speeds is change the processor bus speed settings. Many motherboards allow changes in speed of up to 50% or more, but a processor rarely sustains speeds that far above its rating without locking up or crashing. Also note that, by increasing the speed of the processor bus, you may also be increasing the speed of the memory bus, PCI bus, or PCI Express (or AGP) bus by the same percentage. Therefore, if your memory is unstable at the higher speed, the system will still crash, even though the processor might have been capable of sustaining it.

CPU Voltage Settings

By either increasing or decreasing voltage slightly from the standard, a higher speed of overclock can be achieved in the system. Some motherboards allow adjusting the voltage settings for the FSB, chipset, and memory components, allowing for even more control in overclocking situations. Some motherboards do not allow manual changes to these settings.

Processor Cooling

Heat is a problem in any high-performance system. The higher-speed, processors consume more power and therefore generate more heat. The processor is usually the single most power-hungry chip in a system, and in most situations, the fan inside your computer case is incapable of handling the load without some help. This is where heat sinks and other cooling process come.

Heatsinks

A heatsink works like the radiator in your car, pulling heat away from the engine. In a similar fashion, the heatsink conducts heat away from the processor so it can be vented out of the system. a fan is incorporated somewhere inside your PC to move air across the heatsink and vent it out of the system.  In some systems, the fan included in the power supply is enough when combined with a special heatsink design; in most cases, though, an additional fan must be attached directly over the processor heatsink to provide the necessary levels of cooling. Case fans are also typical in some systems to assist in moving the hot air out of the system and replacing it with cooler air from the outside. The heatsink is normally attached with clips or snap-in retainers. A variety of heatsinks and attachment methods exist.When installing or removing a heatsink that is clipped on, be sure you don’t scrape the surface of the motherboard.

Liquid Cooling

One of the more extreme methods for cooling a PC is to use some form of liquid cooling. Liquids have a much greater thermal carrying capacity than air, and as processors run hotter and hotter, it can be advantageous or even necessary to use a form of liquid cooling to dissipate the extreme levels of heat generated, especially in smaller or more confined spaces.Several forms of liquid cooling are available,including the following:


■ Heat pipes
■ Water cooling
■ Refrigeration
Of all the types of liquid cooling available, heat pipes are the only type that is practical and cost effective in production-level PCs. Water cooling and especially refrigeration are limited to those who are pursuing extreme overclocking and are willing to pay the high prices and put up with all the drawbacks and disadvantages that come with these two options.

Thermally Advantaged Chassis

Chassis that have been specifically designed to improve cooling for the processor by maintaining a temperature of 40°C or less at the processor heatsink inlet are often referred to as thermally advantaged chassis. Using a thermally advantaged chassis allows the processor to remain cool, even under extreme environmental conditions, and it reduces noise. Most modern processors and chassis incorporate cooling systems that can adjust the speeds of the fans.

Best Overclocking Software's :

1. CPUZ and GPUZ
2. AMD Overdrive
3. Intel Desktop Control Center