Overclocking is a collection of methods for making components run faster than the manufacturer intended. Once little more than a hobby for die-hard geeks and value-seekers, overclocking has become a way—sometimes the only way—for performance fanatics to get the system performance they really want/need. With graphics and memory technologies forging ahead at a brisk pace, central processors are quickly becoming the second-most restrictive component in many high-end systems.
If you feel forced into overclocking just to get a high-performance benchmark from the best parts, mid-budget enthusiasts are certain to find their lower-cost parts mind-numbingly slow. Because most buyers can’t afford the best components, the majority of overclockers come from the mainstream market.
There are two groups who overclock out of perceived necessity: those who need more performance than the market provides, and those who need more performance than they can afford to purchase.
Tom’s Hardware puts much of its editorial efforts into testing and overclocking the latest high-end parts, but today we’re going to focus on a few processors that most mainstream readers can afford and enjoy: AMD’s Phenom II X2 and X4, and Intel’s Pentium Dual-Core and an entry-level Core 2 Quad.
Though we’re obligated to tell everyone that overclocking is a great way to put important data at risk, many Tom’s Hardware editors even employ it on their all-important work PCs. Methods that ensure stability are just as important as those that assure longevity, and any data that can't be replaced should be backed up to at least two devices, regardless of whether or not the primary system is overclocked.
All machines wear out, and forcing a component to run beyond its specifications is a sure way to make it wear out faster. In electronics, the biggest source of wear is a phenomenon known as electromigration, whereby ions are slowly transferred from a structure to the adjacent structure under the force of electrical current. Major contributing factors include increased heat and voltage, but the limits of heat and voltage vary with different materials, different production technologies, and expected component lifespan.
Increased voltage allows a stronger signal to be carried between various components, reducing signal loss that can occur as the result of overclocking and thereby allowing higher component operational frequency. As we overclock today’s four processor samples, we’ll discuss the voltage and temperature limits we’ve chosen as well as the expected lifespan, testing each part for complete stability.