So what is overclocking? Overclocking is basically just running a component of your computer above its rated speed. There are several popular types of overclocking: CPU (processor), Memory (RAM), and Graphics card. This guide will focus on CPU overclocking.

The first thing you should understand is how the speed on your computer's processor is derived. The only number you are trying to increase through this overclocking is your processor's clock speed. The clock speed is the "megahertz" or "gigahertz" number that PC manufacturers brag about when advertising their computers.

The BIOS menu

This number is internally calculated by two separate numbers: the Front Side Bus (FSB) on your motherboard, and the multiplier set on your CPU. The product of these two numbers gives you the clock speed of your computer. For example, a FSB of 150 and a multiplier of x20 will give you 150x20=3000 hertz (3 gigahertz). An FSB of 200 and a multiplier of 15 will ALSO give you a clock speed of 3 gigahertz. In the screenshot above, the clock speed is 148x16.5=2442 hertz.

For most CPUs, the multiplier has an upper lock so you cannot go above a certain multiplier. Therefore, most people tinker with the FSB instead. By raising a motherboard from 150x20 to 160x20 will increase the clock speed from 3.0 gigahertz to 3.2 gigahertz.

Also note that you cannot overclock on every motherboard. Most PC manufacturers block access to these functions in the BIOS menu so if you have a Dell, Gateway, HP, Sony, etc. then you are out of luck. A generic or custom built PC should be fine.

To access the BIOS menu (that blue screen you see above), press Del or F2 when your computer is booting (before the beep in the beginning). Once the blue screen appears, you can view all the overclocking options by going into the “Cell Menu” (or some other title depending on motherboard). Inside the cell menu, you will see the FSB and multiplier options you see in the screenshot above.

CPU-Z

Before you make any changes in your BIOS, exit back out of the BIOS and go into Windows. Download the programs CPU-Z, CoreTemp, and Prime95. CPU-Z will give you all the information you need about your processor and memory including clock speed, CoreTemp reveals the temperature on your processor. This will tell you if your CPU is getting too hot. Prime95 is a stability tester. It will tell you if your CPU is stable at the current clock speed (and it will give it 100% load so you can combine it with CoreTemp to figure out your processor's load temperature).

You should also be aware of your CMOS resetter jumper or button on your motherboard. It will be the thing you press to reset everything to default values if your computer does not boot. You can also take out the CMOS battery on your motherboard for a few seconds to achieve the same effect.

Being said all that, you are now ready to begin overclocking your CPU. Restart your computer and go back into the BIOS. Go into the Cell Menu as before and increase your FSB by 5 hertz. Save and exit from the BIOS. Let Windows load up and open up CPU-Z. See if it reflects the changes. If it does, restart the computer and return to the Cell Menu. Increase the FSB by another 5 hertz and save the changes. Then boot into Windows again and check CPU-Z if it reflects the changes. Repeat this process until either your computer does not boot up or Windows no longer loads up.

When this happens, reset your CMOS as stated in the paragraph above. After you do that, go back into the Cell Menu and put that the last WORKING value you entered. This should be 5 less than the value that caused the crash. After doing so, save and exit the BIOS and let the computer go into Windows.

In Windows, open up Prime95 and CoreTemp. Run the Small FFT test in Prime95 for one hour and gauge the temperature in CoreTemp. If the CPU does not go over 65 degrees Celsius and Prime95 does not crash or show any errors after one hour, you are done. If an error shows up, return to the Cell Menu and decrease the FSB by 2 and retry Prime95 again.

There is a way to increase the max stable clock speed on your CPU even more by upping the voltage on your motherboard. But without a proper cooling system, it could be dangerous for your processor. For this reason, I will not include the instructions in this guide.

Well that's all you need to know as an intro course to CPU overclocking. I hope this has been useful for clearing up some of your questions on the matter and I wish you luck pushing the max performance from your processors. Good luck and have fun! ;)