June 28, 2010, 1:58 PM — Overclocking refers to pushing your computer components harder and faster than the manufacturer designed them to go. The initial pitch is seductive: Buy a slower, lower-cost CPU; juice up the clock speed; and presto! You have a cheap, high-end processor.
Of course, it's not that simple. Overclocking can certainly speed up your system (and save you some cash in the process), but only if you do it right.
We're going to talk about some of the basics of overclocking--what it really is, some of the basic math behind overclocking and how you might push your own system a little harder and faster. The goal here is to get better, stable performance for your money. After all, it doesn't matter how fast your computer runs if you have to wait for it to reboot from a crash every 10 minutes.
Though overclocking is a complex topic, we'll to keep the discussion here as simple as possible. We won't go into great detail on voltage changes or power issues, or examine the intricacies of memory timing. And we're not going to show you how to get your cheap Celeron up to 8.2GHz.
We will, however, talk about core CPU multipliers and memory clocks, and how the two relate to each other. Memory and CPUs are intricately interconnected, and simply pumping up the speed of one or the other may not yield the performance improvements you want to achieve.
What Is Overclocking?
Simply put, overclocking means setting your CPU and memory to run at speeds higher than their official speed grade. Almost all processors ship with a speed rating. For example, an Intel Core i7 860 runs at 2.80GHz out of the box. Overclocking a Core i7 860 means pushing it to a clock speed higher than 2.80GHz. This article will focus primarily on CPU overclocking to illustrate the core concepts (pun intended).
Processors don't instantly melt when you overclock them because a modern CPU's speed rating specifies the speed at which every processor in the same manufacturing batch cano run--a number that's likely to be considerably lower than the maximum speed that your specific processor is capable of.
In general, CPU yields are so good these days that the nominal speed grade locked into a chip may be far lower than the speed that the chip is capable of running a computer at. In other words, since the statistical distribution in the manufacturing process is skewed toward better-quality chips, odds are that your processor is better than its rated speed.
Disclaimers and Myths
Before we start adjusting core multipliers and memory clocks willy-nilly, let's pause for an important disclaimer: