Tutorial: Overclocking via Processor Multiplier

Manipulating the processor multiplier is the optimal overclocking method, since it
neither interrupts nor changes motherboard-level bus speeds. The processor
multiplier number that you select in your BIOS Setup menu (see Figure 1), or via
dipswitches or jumpers on your motherboard, will determine your processor's
operating frequency since the processor will multiply the motherboard's front-sidebus
frequency by the processor multiplier. Therefore, by increasing the processor
multiplier beyond its default setting, you will increase your processor's operating
frequency beyond its default as well.

Figure 1

System stability can only be compromised if the maximum operating frequency of the
processor's core is exceeded. Maximum performance potential is best realized by
combining several overclocking techniques, but multiplier overclocking is a favorite of
many enthusiasts because it creates fewer problems.

Depending on your system hardware, overclocking through multiplier manipulation
alone may be impractical. For example, the most recent Intel processors feature a
locked core multiplier, except for the earliest Pentium II-based designs and the
occasional unlocked engineering sample that surfaces in the underground market. All
current and near-future Intel processors are completely locked, thus forcing owners
to rely on front-side bus overclocking techniques.
Knowing your motherboard is critical to assessing the overclocking potential of any
current AMD Athlon system. The majority of Athlon-based motherboards lack the
features users need to control multiplier values. The required circuitry increases
manufacturing costs. Those willing to risk hardware-level modifications can overcome
this limitation.