20 Things They Don't Want You to Know

We reveal some of what vendors are keeping mum, such as: You never have to pay full price, extended warranties rarely pay for themselves, and the big sites do have customer service numbers.

Illustration: Dan Page

Psssst! Wanna know a secret? How about a whole bunch of them? Sadly, the Colonel's Secret Recipe and Dick Cheney's Secure Undisclosed Location remain shrouded in mystery, but I'm going to spill the beans about a bunch of things that technology companies would rather you didn't know. These insider tips will help you cut through hype when you shop, save money when you buy, and get the most out of products you already own.

Your CPU May Be Much Faster Than You Think

Photograph: Rick Rizner

Here's a CPU manufacturing secret: Most CPUs can be overclocked to run at least a bit faster than usual, giving your PC a free speed boost. And on some rare occasions, low-end chips are capable of running just as fast as much more highly priced CPUs. But while overclocking can speed up your system, note that you must take care to properly cool your PC, or you might damage the CPU--and most system warranties won't cover that damage.

The big speed jumps usually come along when Intel or AMD has transitioned to a new manufacturing process and is getting great yields on even its high-end chips. When that happens, slower CPUs that use the same technology are ripe for overclocking. The classic example: Intel's Celeron 300A chip, a 300-MHz CPU that overclockers routinely ran at 450 MHz. Check in periodically with enthusiast sites like Anandtech (and HardOCP--they go wild when those situations arise.

To overclock most of today's CPUs, you bump up your computer's bus speed, either through the system's PC Setup (or BIOS) program or via a Windows-based utility such as NVidia's NTune. (See "Secret Tweaks" in our March 2005 issue.) Each time you increase the speed, you should use a utility like Motherboard Monitor to check the CPU's temperature while you stress the system by encoding video or playing a 3D game. If the core temperature rises above 60 degrees centigrade, or if you experience any system instability (crashes, corrupt graphics, etc.), roll back to the next-lowest setting and stay there.

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