SetFSB allows to change your computer's Front Side Bus (FSB) speed. The utility supports a wide range of chipsets and is easy to use. Just move the slider to set the desired FSB speed and see the resulting CPU speed.
If you are a beginner, do not use this software. This software is for power users only. Use "SetFSB.exe" at your own risk.
As of 2017, this has not been updated and is no longer sold and was released as freeware. Don't let that make it seem like a good idea, however. It's unsupported, unbuyable and not recommended. It's also not for the beginner. You've been warned.