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Overclocking Done Right

There are a few questions to ask yourself before you can actually get to overclocking your system. First, does your motherboard BIOS offer settings to overclock your system? Second, are you willing you void your processor’s warranty? If you can answer yes to both these questions, here are a few pointers that will ensure you get the most out of your computer’s processor.

Actual Processor Speed

The way that your processor’s speed is determined is nothing more than a simple multiplication problem. For example (computed this way for every example in this article) a 2.8 GHz Pentium 4C has a multiplier of 14. This number is locked into the processor and is one of the primary differences between higher speed processors and older, unlocked ones. This multiplier is then multiplied by the front side bus (FSB) speed. The FSB of a stock P4C motherboard is 200 MHz. This FSB speed is multiplied by the locked multiplier, which will give the rated 2.8 GHz of the P4C.

But wait - you say. The retail box for the P4C motherboard is 800 MHz, not 200 MHz. This is because the FSB is “quad-pumped” (4 times as many bits per clock cycle) which yields the advertised 800 MHz FSB. The Athlon XP FSB is “dual pumped”, by the way, so Athlon XP FSB are advertised as running at twice their actual speed.


Time To Overclock

There are two ways to overclock - raise the multiplier, or increase the FSB speed. The only way you can raise the multiplier is if you get very lucky and can find a non-production version of the processor that you own (which is HIGHLY unlikely, unlocked processors are usually for experimental or evaluation purposes only.) So that leaves the rest of us left with raising the speed of the FSB of our motherboard. In your BIOS, you will need to find the option to view the current FSB, and then raise it. Keep this in mind: you raise the FSB speed at your own risk, since every increase in FSB clock speed increases your chance of overheating or instability problems.

In my overclocked P4 system, the actual FSB speed is 243 MHz. That is then multiplied by 14 for a total processor speed of 3,402 MHz or 3.4 GHz. The total FSB speed is 243 multiplied by 4 (quad pumping) for an effective FSB of 972 MHz.


There are two other things to consider while overclocking, namely what voltages your processor and RAM are currently using. Voltages are very important when overclocking; naturally, the higher clock speeds require higher voltages. Bumping up the voltage can be the difference from making a 2.8 P4C run at 3.36GHz or at 3.5GHz. If raising the CPU voltage doesn’t work, try raising the RAM voltage also. However, NEVER raise the voltage more than one step at time; voltages that are excessively high can make CPUs or RAM to go up in smoke. All CPUs and RAM modules have a range of safe voltages - look on the retail packaging or look it up on the Intarweb before you proceed to raise voltages.

Was It All Worth It?

After overclocking, every hardware guru wants to see how much he or she has gained. I recommend SiSoftware Sandra , as this program will test every aspect of your computer. If you run this program and take a look at the Cache and Memory benchmark, you can compare your processor to other similar processors. Another piece of software that is very useful to evaluate your processor is CPU-Z. Again this program will inform you of the current speed and voltages of your processor. Looking at CPU-Z’s memory tab, you will see a box that says FSB:DRAM. This tells you the ratio of your effective FSB to the speed of your RAM. This computer is configured at a 3:2 FSB to DRAM ratio (243/162). With RAM speeds soaring into the 500 MHz zone it is more realistic to get lower ratios with an overclocked system.

CPU-Z Memory Tab SiSoftware Sandra

The Deal

Overclocking is an easy way to get more bang for your buck, but it voids your CPU’s warranty, so be careful. Overclocking is becoming easier every day; start slowly, don’t be afraid and don’t forget to find the jumper to clear your BIOS setting if you have gone beyond your system’s safe clock speed. Good luck and happy overclocking.

written by The Freek
edited by the_doc