The IBM ThinkCentre is a line of desktop computers designed for use primarily in business environments. These tend to be low-to-mid-range desktop computers, which means that they become obsolete fairly quickly. Rather than scrapping your IBM ThinkCentre in favour of a new computer, you can extend the life of the ThinkCentre PC by overclocking the CPU.
Restart the IBM ThinkCentre PC.
Enter the BIOS by pressing the "F4" function key when you see the IBM splash screen at start-up.
Enter the "Advanced BIOS Options" (or "Advanced Chipset Settings", depending on the ThinkCentre model you are using) using the keyboard's navigational arrows. Highlight the option, then press "Enter" to go in to the menu.
Highlight the "Front Side Bus" option and press "Enter." Enter a new Front Side Bus speed using the keyboard's numerical keys or the up/down arrows. Once the new speed is set, press "ESC" to back out.
Press "ESC" to go back to the main BIOS menu, then press "ESC" again to exit the BIOS. When prompted, press "Y" to save the new settings and reset the PC.
You can gauge the CPU speed by multiplying the Front Side Bus speed and the "Multiplier" number. Increase the Front Side Bus speed in small increments to better get an idea of how far you can push the CPU.
Overclocking a CPU will increase the heat generated by the chip. Counter this with additional cooling fans, a third-party CPU heatsink and regular PC cleaning.