Higher FSB means higher Vcore?

hitechjb1 said:

Why high voltage is needed to run higher CPU frequency (and maybe higher FSB)

Higher Vcore is necessary to get to higher frequency but not sufficient for stability. To get to stable high frequency under load, it requires both high Vcore and low enough temperature for a given CPU and for a given cooling setup.

This is why:

CPU (chip) is made up of many transistors (towards 100 millions for Tbred/Barton, 100+ million for A64) forming logic switches to perform logic operations. Physically, each transistor is connected to some capacitors which are inherent in the transistor gate dielectric and coupling between connections and the underlying silicon. In order for the transistors to switch and perform the required logic function physically in a given CPU cycle, electric current is needed to charge and discharge these capacitors (100 millions+) via the corresponding transistor switches.

Such switching current (usually known as Idsat) through a transistor depends on Vcore, the higher the Vcore, the larger the current (a property of transistor, without going into details here).

That is,
the higher the Vcore is,
the higher the current,
the shorter the time to switch a transistor to do a logic operation,
the shorter the cycle time of a pipeline in a CPU,
the higher the CPU frequency (and FSB).

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