A Basic Guide To Overclocking and System Building

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Detailed How-To – Craig Garbella


This is a guide I have put together to aid people in building and overclocking their computer. It uses a step by step approach to things and should be easy to follow. If there are any questions about where my experiences come from, feel free to email me.

System Setup

Whether you buy your computer from a company such as Dell or Compaq, or build it yourself, overclocking is still possible (although difficult for proprietary systems). For those people who build their own systems, I will provide a basic installation and setup checklist of thing to do to ensure a proper system setup. By no means is this a complete step by step guide, so it would be strongly suggested to research further if you have no prior knowledge to system building and you wish to attempt it now.

Products Needed:

  • CPU
  • Motherboard
  • Heatsink and Fan
  • Thermal Grease
  • RAM
  • CD-ROM(s)
  • Floppy Drive
  • Case and Power Supply
  • Hard Drive
  • Keyboard, Mouse and Monitor
  • Soundcard
  • Graphics Card
  • Operating System
  • Product Drivers

Optional items are those such as:

  • Speakers
  • Printer
  • Modem
  • Ethernet Card

as well any other adapters desired.

First of all, the products are to be unpacked. Usually, the power supply comes installed in the case, but if it is not, then that should be the first thing installed. Once that is done, install the motherboard into the case.

Now is a good time to install drives, such as CD-ROM’s, hard drives, and floppy drives. Screw them into place, hook up power cables as well as IDE cables. Don’t forget to attach the cables to the Motherboard.

The next thing would be to hook up the power cables from your power supply unit to your motherboard. Don’t forget the second power cable for your Pentium 4 – it is a four wire cable that is to be plugged into the motherboard as well.

Now for the CPU: For the Pentium 4, there are about 2-3 pins missing off the bottom of the CPU on one corner. That is so you can line it up with the motherboard socket for installation – it only fits one way. The socket has a lever that is to be lifted, then the CPU set in place, followed by the lever being pushed back down to it’s original place. The CPU should almost drop in place – if you encounter resistance, check its position in the socket.

Apply a thin layer of thermal grease to ensure complete contact between the processor and the heat sink. Now you can install the heat sink and fan, either the Intel or an after market version of your choice.

Craig Garbella

Insert RAM, Graphics Card, and Sound Card as well as any other cards, such as an Ethernet Card, into place. Lastly for physical installation, the power switch, reset switch, case speaker, power light, and hard drive light should be hooked up. The motherboard book will have the location as to where these go. Now you can put the case side back on and hook up the mouse, keyboard, monitor and speakers, printer, etc., if needed.

For the software side, the Operating System (OS) is to be installed first, followed by drivers for the motherboard, graphics and sound card (if the motherboard has on-board sound or other components, drivers will be on the motherboard’s CD). If you are using Windows 2000 or Windows XP, drivers for CD-ROMs, keyboards, mouse and Ethernet Cards will be automatically installed; otherwise, for older operating systems, the components will have come with a driver on either a floppy or a CD to be installed.

Now the overclocking begins!

Overclocking Process

The first thing suggested to do is to realize a realistic over-clock for the computer. By visiting Overclockers.com, it is possible to view other’s results with the same CPU. Overclockers.com gives an average overclock, so it is advisable to determine a realistic goal from these results. This is not to say that one should not have an ultimate goal, but to meet the primary goal first could simplify the overall process.

One aspect to keep in mind is that different people have different methods of cooling. This is a very important aspect of overclocking and one should determine their goals based partly on the cooling method of choice. Cooling is going to be covered in-depth below.

Once the idea of where to try overclocking the CPU is determined, figuring out what is to be done to achieve said goals is next.

With Intel’s Pentium 4 processor, there are to date two different Front Side Bus (FSB) speeds and a locked multiplier. Together these determine the overall clock speed of the CPU.

For example, the Pentium 4 2.4A has a multiplier of 24 and a Front Side Bus of 100 MHz (Quad pumped, meaning 100 * 4 = 400 MHz). When the Front Side Bus is multiplied by the Multiplier, one gets a speed of 24 x 100 = 2400 MHz, or 2.4 GHz. The Pentium 4, 2.4B has a multiplier of 18 with a Front Side Bus of 133 (Quad Pumped, meaning 133 * 4 = 533 MHz). With the same calculation, you get an overall clock speed of 2400 MHz or 2.4 GHz.

This is how the initial speed is calculated. The 2.4A is the older of the 2 processors and the 2.4B is the newer model. Intel has created a faster front side bus which, in turn, runs the system faster – 133 MHz vs 100 MHz.

Therefore, one could say that the 2.4B is a better processor than the 2.4A at stock settings. A possible goal with the Pentium 4 2.4A is to achieve a Front Side Bus speed of 133 instead of the stock 100. This would then make the processor 24 * 133 = 3192 MHz or approximately 3.2 GHz.

It is important to note that only the Front Side Bus of the Intel Pentium 4 can be changed, not the multiplier, as Intel has locked it.

Also, RAM speed is determined by the Front Side Bus of the computer. Most RAM today is DDR RAM. One must make sure the RAM is run within its specifications, or system stability may be at sake. It is possible to overclock RAM as well, but keep in mind that if the system is not stable, overclocked RAM will have to be considered as a possible reason.

To change the Front Side Bus, one enters the computer’s BIOS before boot-up, goes to the Frequency/Voltage Control section (which may be named slightly different on various motherboards). Here the Front Side Bus can be changed to the desired speed.

Each processor performs differently, so even if a friend can overclock with the same CPU, this one might not do the same, or may do more. With a change in the Front Side Bus, it is extremely important to unlock the Voltage setting and change it, depending on how fast the computer is being set.

Almost always, the CPU will require more voltage to perform stable at an overclocked speed. This will be discussed more below.

Craig Garbella

Now is a good time to find out what how fast to run your RAM. In the same section of the BIOS, one can change RAM settings. There are different ratios that can be found in the motherboard manual.

For example, if the RAM is DDR 333, this means that it can perform at a speed of 333 MHz. But DDR RAM is double pumped, so if it was running at a 1:1 ratio with the Front Side Bus at 133, the RAM would be at 266 MHz.

Different motherboards have more or less options, so choose the best for the particular situation. I would suggest leaving the RAM at its designed speed, and then overclock the RAM, if desired, after it has been determined that the system is stable. This is to ease the process of stabilizing the system by only changing one factor at a time.

Once the settings are changed, save them and exit the BIOS screen. Now the computer should reboot. Look carefully at the POST screen to see if it has changed. Now it should read the new overclocked speed of the system. If the new speed has posted, see if the system will log into Windows. The next step in this case would be to move onto sections 2.3 or try to post and get into Windows at a higher speed.

If the computer fails to post, posts at the original speed, or crashes before getting into Windows, go back into the BIOS. Now there are 2 things to try, or a combination of the two things. More CPU voltage can be tried or a lower Front Side Bus.

They work together – one needs more voltage to be stable at a higher Front Side Bus, but it should be kept in mind that the more voltage and the higher the Bus speed, the higher the CPU temperature. High temperatures can make the computer system unstable and/or damage the CPU. With this in mind, adjust the settings accordingly and attempt again to post and get into Windows.


Now that the computer is in Windows, it is time to see if the computer will run stable at this speed. If the computer is not tested, it might crash while doing CPU intensive tasks, such as playing games or running certain programs; therefore it is important to make sure the system is stable.

A common tool to use for testing stability is Prime95. Under the Options menu, perform the Torture Test. Basically the function of this program is to stress the CPU to its limits, making it calculate numbers.

The program has predetermined answers, and compares the CPU’s answer. If a wrong answer is found, the system is not stable and the test will report as failed. In this case, the previous two options are available, either increase voltage or lower Front Side Bus speed, while keeping in mind RAM timings.

The Intel CPU comes with a heat sink and fan that is designed to cool at the stock voltage and speed of the processor. For this reason, one might find to stabilize the system, more voltage is needed, but as the voltage is increased, the cooling might not be sufficient. This can be dealt with in numerous different ways.

The most basic and common solution is to buy a new heat sink and fan. The main factor about the heat sink and fan to consider is the C/W rating. This can be found at various web sites such as Overclockers.com. C/W can be interpreted by looking at two different ratings. Say two heatsinks are rated, one at 0.35 and the other at 0.40. The 0.35 will result in 5 degrees Celsius cooler than the 0.40 when running at 100 Watts.

An Intel CPU typically runs around 50 Watts when at full load, in this case making the difference 2.5 degrees Celsius. Through testing, the author has found that once the CPU reaches temperatures in excess of 60 degrees Celsius, they tend to make errors, so this can be a basic guide as to what is a safe temperature.

This being said, one should note that the Intel Pentium 4, to protect itself, will work slower when it begins to overheat, so the risk of damaging the CPU due to heat is lower than other CPUs.

With the application of a new heat sink and fan, temperatures should become lower when the CPU is running at full load. Now that the temperatures are lower, this will allow for a higher voltage setting, if needed to obtain full stability.

Craig Garbella

In order to conclude full stability, running Prime95 for in excess of 10 hours will usually be sufficient. A minimum of 6 hours should be passed before concluding the system is stable. If the computer crashes, or Prime95 fails, it is then noted as unstable and it’s back to the drawing board to see what adjustments are to be done now.

Another less common solution to a CPU cooling is to use a waterblock instead of an air-cooled heat sink.

Basically, this setup replaces the “normal” heat sink. Instead, the heatsink is much smaller and uses liquid to cool it. There is a water pump, radiator with fan and tubes running into and out of the waterblock. This system typically works much better than air cooling.

Despite this, there are a few reasons why it is not widely used. Primarily, cost is a major issue. A very good heat-sink and fan can be purchased for around $50, whereas water cooling is generally at least $100 for a complete system, and two to three times more for a high performance system.

The second reason is that some people are afraid of putting water inside their computer systems. If a line were to break, or leak, this could lead to the destruction to the entire system.

With these factors in mind, some still choose to purchase a watercooling system. Cooling performance is greater because water is more efficient in moving heat to a large cooling surface (the radiator) than air (heatsink fins). This results in consistently lower temperatures, thereby creating a more stable system at higher speeds.

There are other things to help control temperatures.

Some people find that with air cooling, as the computer works hard for a long period of time, temperatures inside the case rise, causing the CPU to heat more as the air temperature cooling the CPU rises. This causes temperatures inside the case to increase more and ultimately may result in a crash or instability of the computer.

Case fans are a great way to solve this problem. To ensure best results, intake and exhaust fans should be used. Because hot air rises, the exhaust should be placed at the top of the case and the intake fan should be placed at the bottom to create a flow of air from top to bottom. If one fan is at the front of the case and one at the back, this will also aid in creating a flow.

Through an experiment, a cost efficient modification has been found to help lower CPU temperatures. Noting that the air blowing onto the heat sink is right beside a large heat source, the CPU, it can be said that the air being blown is warmer than the air outside the case.

The modification was to cut a hole in the side of the case directly over the top of the CPU, attaching a duct between the CPU fan and the hole in the side of the computer case. This allowed for cooler air from the outside of the case to be drawn in, cooling the heat sink and lowering temperatures by 3-4 degrees Celsius when at 100% load.

To conclude, overclocking is something that can be used to save some money, squeeze some extra performance out of your machine or just to have some fun. Many people take pride in their Mods and overclocks.

An extremely important thing to keep in mind is that overclocking completely voids the warranty of your products. Under no circumstances will overclocking always be possible, and I nor Overclockers.com take any responsibility for damaged components or warranty voids. Overclock at your own discretion at your own expense.

That being said, I hope that I have been able to help you in some ways, and feel free to email me any questions.


Craig Garbella


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