What is overclocking?

Overclocking is the process of running your computer's processor at a higher speed than what the manufacturer told you to run it at. For example, you bought a Pentium II 233 which will run by default at 233 MHz. Overclocking it would mean to run it at 266 MHz (for example) instead which means the processor works faster and therefore makes your PC faster.

The reason you would do this is to improve your PC's performance without having to go out and spend lots of money on a new motherboard and processor. But there is a limit to overclocking. You can get a 5-15% performance improvement, often even more with the right components. Do not expect 50 or 100% increases. If that is what you're looking for, stop reading, get out your credit card and head over to your local PC hardware store.

Now you might ask, if the CPU can run at 266 instead of 233, why did the manufacturer not sell it as a 266 and charge more money for it? Well, the way the CPU gets their speed rating works like this:
The chip will be tested after it comes out of production to see how fast it can run. If it fails at 300 (for example), it will be tested at 266. If it fails at 266 (and maybe just by a hair), it will be tested at 233 where it passes without problem. Then it will be sold as a 233.

When you overclock the chip, you call the manufacturer a liar and claim that you can run the chip faster than they tell you to.
Of course when you overclock, you want to be able to run at the higher speed for more than just 10 seconds. Successfull overclocking means that you can run at the higher speed reliably and indefinitely without the slightest hiccup.

The main problem with overclocking is that running at a higher speed means that more electricity flows through the chip as it works harder which causes the CPU to get much hotter than at the approved speed. This can cause the CPU to overheat and act erratically, causing weird error messages, program crashes, random rebooting, all they way to not booting up anymore. I will address this issue later in the "cooling" section.

Now that you know what overclocking is, let's move on to the next section and find out what you need to do this.