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OVERVOLTAGE, AND "SAFETY"

This section summarizes the dangers of overvolting.

One remarkably common misconception about overvoltage, is that there is a number set in stone for each particular component, a number which dictates the "safe" overvolt that one can use with any specific piece of hardware. This is not true.

It is partially valid however. Specific types of hardware are almost always similar in their limits, granted no manufacturing defects. However, each piece of hardware is still unique to small, varying degrees. Being able to find your individual hardware’s unique "safe" voltage limit is useful, when squeezing every last reliable speed step-up out of our of your hardware.

When we overvolt, we rely on the integrity of our hardware. We assume that it is of high quality, without manufacturing defects, and that it is capable of withstanding a large overvolt without sustaining damage. Most of the time, this is the case. There are always exceptions. It is speculated that hardware which is damaged through overvolting, already contained small defects or weaknesses that were only made apparent, or made worse, when the hardware becomes strained through overclocking, and overvolting. There is no accurate way to tell if your specific piece of hardware has such flaws. Sometimes, we get unlucky. For the most part though, ‘healthy’ hardware is capable of running smoothly for years and years with a considerable overvolt in place.

Overvolting is dangerous, and inherently risky. As soon as you overvolt your computer hardware, you void your hardware’s warranty, and run the risk of sudden hardware death. That risk is small if you are cautious and smart with your overvolting, but it is always present nonetheless. The words overvolt and safe should really never be used in the same sentence. For this guide, I will refrain from saying safe, and will use "safe" instead – there are always risks, make no mistake.

Speaking from a personal perspective, I have overvolted almost every single piece of transistor-based and overclockable hardware that I have ever owned. I have never had a hardware death as a result of overvoltage (although I have killed more than my fair share of computer hardware...), and barring bad luck, you shouldn’t either if you take your time, and are careful.

More voltage has the nasty side effect of creating heat. Our transistor based computer hardware does not do well with high temperatures, and can sustain damage from lengthy exposure to high temperatures. The "safe" temperature to run our hardware at is theoretically directly related to how much voltage you are giving your hardware – the larger the overvolt, the cooler you should be keeping your hardware in theory. There is certainly no number or ratio set in stone for this – common sense is your only reliable ally – "if it’s stable it’s safe" is an excellent guideline. Stability is a reliable and consistant standard to use for the measurement of safety, which is not a "variable" that is measureable directly.

Overvolting also has the effect of increasing the rate of electromigration within our hardware - both high current density and high levels of heat will accellerate the rate of electromigration (and both of these variables are directly increased through overvoltage).

Electromigration increases the resistance of the metal interconnects (miniscule wires and contacts - the conductive signal pathways inside of our transistor-based processors and memory) within our transistor-based hardware, which can mess up processor operation. Remember the transistor tolerances mentioned in the first section (If you didn't read the first section, don't sweat it)? When signal resistances within our transistor-based hardware are increased, our signal strength can fall outside of our hardware's transistor VDD tolerence as a result. Electromigration can also eventually cause interconnects to break entirely - and a broken interconnect pretty much means a dead piece of hardware (you cannot send a voltage high signal down a broken interconnect!). Electromigration is a long-term issue, an increased rate of electromigration means a shorter lifespan for your hardware. Electromigration is not a huge issue with modern hardware due to the high quality of the materials used in the construction of (most) modern hardware - although it apparantly does still occur, albeit at a slower rate. A very detailed and highly technical explanation of the electromigration effect can be found HERE, (thanks Gnufsh for the excellent resource!).

When overvolting, it is important that one has adequate cooling on their hardware. A good rule of thumb is "voltage doesn’t kill hardware, heat kills hardware" (and likewise, "overclocking doesn't kill hardware, heat kills hardware"). This simple rule, of course, is only applicable if one overvolts their hardware within reason, "reason" being actively paying attention to what your hardware tells you through its responses to overvoltage.

All the doom and gloom done with, lets move on to our last and most interesting section of the guide, Overvolting Technique in Overclocking.