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Overclock your PC hardware

Posted on 11 Feb 2009 at 12:37

Once you push to clock settings that are on the cusp of stability, you can take things a step further and try tweaking the voltage settings to wring an even higher frequency out of the system - most motherboards allow you to adjust both processor and memory voltages. Overclocking and overvolting go hand in hand: when transistors are driven harder with a higher voltage they can run at increased frequency. But be warned that overvolting can cause problems as well as solve them.

The total power dissipated as heat increases with the square of the voltage applied to a transistor. That means a seemingly small increase of a few tenths of a volt can greatly increase the power dissipation - and thus heat - your heatsink has to cope with. It may make the transistors in the processor switch more reliably at first, but if the heatsink can't cope with the extra power dissipation it will quickly overheat and automatically go into thermal shutdown - the whole PC will simply switch itself off to protect the CPU from permanent damage. Overvolting memory isn't recommended, as it doesn't have the same overheating protection.

You should check in the BIOS to see what your options are with regard to thermal control, both with the speed of your CPU heatsink and case fans. The vast majority of modern motherboards give you the option to manually fix fan speeds at a given level, or to allow the BIOS to control them according to system temperature. For the best overclocking potential, you want your fans to be shifting as much heat away from the system as possible.

A great utility to monitor both your fans and system temperatures during and after an overclock is SpeedFan, which you can get for free at www.almico.com/speedfan.php. It doesn't work with all motherboards, but if yours is supported you can make it control your fans, and its icon will sit in the System Tray and display the temperature readings of your hardware as reported by its onboard temperature sensors.

If you manage to overclock the PC to the extent that it won't boot at all, don't panic immediately. Recent motherboards can detect when they've failed to boot a few times in succession and automatically reset the BIOS to its fail-safe defaults. If that doesn't happen after a couple of attempts, all motherboards have the facility to reset the BIOS manually, usually by physically moving a jumper link on the board, or removing the CMOS backup battery.

Remember to go in small increments when you're overclocking. It also pays to write down the settings you're using as you go along, because you'll lose them all when you inevitably need to reset the BIOS.

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