Custom PC's Ultimate Core 2 Overclocking Guide

Posted at: Wednesday 31st October 2007 by Alex Watson

Not sure where to begin when overclocking? Alex Watson uncovers the dark art of coaxing more speed out of your PC's components for free.

The benefit of overclocking is clear: you get the performance of a more expensive product from your components, and all it takes is a little tinkering. Of course, there's a catch: Satan doesn't claim your soul and we won't give your details to the RIAA, but forcing a component to run faster than its rated speed puts it under added strain, increasing the risk of damage and decreasing its lifespan. The more you overclock a component, the higher the risk. However, these risks can be offset by understanding how overclocking works, what overclocks well and how to make sure everything is properly cooled.

This article is intended to be a guide for those who are new to overclocking. We'll focus on Intel's Core 2 CPUs, since at the moment, they offer the best combination of price and performance, and we covered overclocking AMD's Athlon 64 architecture in detail in our previous feature. If you have a Core 2 Duo or Quad in your PC that still runs at stock speeds, and you're keen to get more out of it, this is the article for you. By the end of it, you'll be comfortable with tweaking a wide range of controls in order to push your CPU far faster than it currently runs. There's quite a lot of theory and background material in this guide, so feel free to skip ahead if you want to get stuck into the overclocking itself; however, I'd advise reading the whole feature, as it will provide you with the background knowledge you need to get the best out of your system and an understanding of the technical terms used.

Absolutely FABulous

Overclocking is the process of forcing processors and other ASICs (application specific integrated circuits, which is the technical term for chips such as the Northbridge) to operate at frequencies higher than those specified by the manufacturer. In order to understand how it works, it's helpful to understand how chips are manufactured and how they work.

There are contradictions involved in the manufacture of computer chips. Some of the most technologically sophisticated and precise factories in the world, known as fabs (short for 'fabrication' plant) make CPUs, but the results are surprisingly variable. It's an expensive, difficult and delicate process, but market conditions mean that the manufacturing process has to be carried out to an aggressive schedule and on massive scale. It's these tensions that create the gaps for overclockers to exploit.

When Intel and AMD design a CPU core, it will be sold in the shops at a variety of different speeds. For instance, dual core Core-architecture chips range from the 1.86GHz Core 2 Duo E6320 to the 3GHz Core 2 Duo E6850. It's commercially important for Intel and AMD to offer a range of CPUs at different prices, but the reason for these chips varying in cost is partly related to the difficulty of their manufacturing process. When a CPU rolls off the production line at the fab, it's tested to find out the speed at which it can run. As it's harder to make high-speed chips, there are fewer dies capable of running at 3GHz than there are at 1.86GHz, and their scarcity makes the faster chips more expensive.