The obvious but often ignored question: What is Overclocking and how does it work?

Overclocking, in general terms, is running something at a higher frequency (i.e. faster) than the manufacturer’s recommendations. While this may immediately seem like as bad an idea as putting a 300-lb weight lifter in a chair made for people under 225-lbs, there is something special about computer chips that makes the undertaking far less risky.

CPU manufacturing, while requiring absurdly high precision, doesn’t deliver precise results. Intel or AMD don’t decide how much of each chip to make at what speed. For any particular family, like Wolfdale E6x00s or Denebs, they make them all to run as fast as possible. Since all of the chips that come off the line don’t function at the same speed, they are tested and sorted by speed in a process called “binning.” If you are selling CPU family XYZ in 2.8, 3.0, and 3.3 GHz versions, any chip testing reliably from 2.8 to 3.0 goes in bin a, 3.01-3.3 in bin b, and over 3.3 in bin c.

You probably see where this is going. If you just bought the 3.0 GHz chip, it is entirely possible that it will run at 3.297 without breaking a sweat. It gets better though.

Picture, if you will, a lumber company that sells its own products online. Like the CPU manufacturer, they grade their lumber into categories including FAS (the best), No.1 (furniture grade), and No. 3 (flooring). Obviously FAS is the most expensive, but they don’t sell a lot of it. Since the goal, when milling logs, is to get the most and best woods from them, they often have a surplus of a FAS and run out of Nos. 1 and 3.

If they list the Nos. 1 and 3 as out of stock, people with lesser needs and smaller budgets won’t step up to the FAS, but go elsewhere. The store could offer the FAS at the same price as the out of stock wood, but then they would lose the money from those ready to buy the more expensive product at the original price. So the store starts putting better grades of lumber, at random, in with the lower grades. That way they can sell as much wood for as high a price as they think possible, which is just good business.

If a customer notices that some of the wood is better than what they paid for, they are unlikely to complain. In fact, the lumber firm could develop a reputation for selling better than expected products.

Making sure we get all the saw dust off before we go from the mill back to the semiconductor fabrication cleanroom, we now see that our CPU could indeed be FAS when we only paid for No.1, or a 3.3+ GHz when we only forked out for a 2.8 one.

Overclocking, at least while maintaining stock voltages (more on that later), is not really about pushing the envelope, but discovering the chip’s actual potential.