I'm sure Tweak3d will have a lot of articles on overclocking but I'll attempt to give you some super basics on the subject.
Overclocking is running some component or a combination of components/busses on your computer outside of manufacturer specs. Basically you're pushing the speed limits of some aspect of your system. Every system has certain tolerances but it is always guaranteed to run at its rated speed. More often than not, the components can run faster than spec'd.
Generally, "easy" overclocking a computer involves changing one or two settings: The CPU clock multiplier, and the Front Side Bus (FSB) speed. CPU speeds (ie 1.53Ghz) are a function of the FSB. A 1.53Ghz (AMD AthlonXP 1800+) CPU runs at 133Mhz*11.5 or ~150Mhz*10. Overclocking of AMD processors currently involves either increasing the clock multiplier by unlocking the chip, or increasing the FSB, or a combination of the two (best option for most people).
If you want to overclock, spend a little extra money and buy good RAM. Buy RAM that's rated to run at CAS2 at 150Mhz or 166Mhz or even higher depending on what speed you're aiming for. Corsair is my favorite though Samsung, Mushkin, and Kingmax all make "overclockers'" RAM. One important thing to consider is that when you increase the FSB, you are also (there are now exceptions) increasing the AGP and PCI bus speeds since these are proportional to the FSB. The AGP is generally 1/2 or 2/3 * FSB while the PCI is generally 1/3 or 1/4 * FSB. When you increase the FSB you not only put stress on your CPU, but also on almost every other component in your system. You can only increase your FSB as much as your least tolerant AGP, PCI, RAM, CPU component can support. This is where the clock multiplier comes in to play for AMD systems.
Intel has clock locked their CPUs since the first Pentium 2s. AMD has the clock locked on most Athlons aside from MP cpus but, as you've probably read, it is trivial to unlock an AMD CPU. By increasing the clock multiplier and leaving your FSB alone you effectively speed up your CPU but leave everything else in your system in spec. This is convenient if you have a finicky PCI card but is not the optimal solution. You really want to increase your overall bus speed (especially your memory speed) since this will result in a much larger overall performance increase than just CPU Mhz alone.
Lowering the clock multiplier can also be beneficial. By lowering the multiplier you can go to very high FSB speeds without pushing your CPU too hard or you could be running an older 100Mhz Athlon CPU on a 133Mhz board. That's why I mentioned the 150Mhz FSB with the Athlon at the beginning. 🙂
For each aspect of your system, increasing the voltage to a certain component while overclocking can increase your stability up to a point. Many motherboards come with settings that allow you to increase the voltage going to the CPU, RAM, and AGP bus. When overclocking you obviously will be generating more heat. Your system will become less tolerant to temperature changes if you really stress your components. Efficient cooling is a must or just leaving the side of the case off works well too. 😉 A quality power supply is also important but don't go to the extremes that many people will probably recommend. A name brand 300-350W PSU is more than enough for most setups. I personally use a Powerman 300W PSU that came with an InWin full tower a few years ago on my XP1900+ system.
That should be a pretty accurate general intro to overclocking. The best way to overclock is to take things in baby steps and do stability testing each step of the way. Remove all non-essential components if you think one of them might cause problems. If you can change the CPU Multiplier increase it until the CPU becomes unstable. Then lower it way down and increase the FSB until your system is unstable. Then figure out the correct multiplier for the fastest FSB you attained and you should be in the ballpark of your max overclock. It can be tedious but I think it's pretty fun. 🙂
Gaidin
