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A 4.1 GHz Dual Core at $130 - Can it be True?

133 MHz FSB: Perfect For Overclocking

Our overclocking project with the Pentium D 805 starts with a front side bus speed of 133 MHz (533 QDR).

FSB clock speed settings may be applied through the BIOS software. Here's an example from an Asus motherboard.

Using programs from the motherboard vendor, or other tools, you can even change the FSB clock rate while Windows is running. Here's an example of Gigabyte's EasyTune 5 program at work on this task.

The following table provides an overview of some of the mathematically possible CPU clock rates that result from raising the FSB clock rate.

Pentium D 805 with 20x Multiplier
FSB clockCPU clock
133 MHz (Default rate)2.66 GHz
140 MHz2.80 GHz
150 MHz3.00 GHz
160 MHz3.20 GHz
166 MHz3.33 GHz
170 MHz3.40 GHz
180 MHz3.60 GHz
190 MHz3.80 GHz
200 MHz4.00 GHz
205 MHz4.10 GHz
210 MHz (THG clock)4.20 GHz
215 MHz (Maximum boot clock)4.30 GHz

At first blush, overclocking such a small and cheap CPU to 4.1 GHz seems impossible. Nevertheless, the numbers don't lie, and if you consider the ancestry of this CPU more carefully, this kind of overclocking becomes easier to understand.