gamerk316 :
A Hertz is the measure of the time it takes for the CPU to cycle (IE, from a high power state to a low power state). At the start of this cycle, the CPU receives the instructions it is to perform, so a higher cycle rate will give the CPU instructions at a faster rate, theoretically increasing performance.
Instructions Per Cycle is the term used to measure how many instructions a CPU can perform in a single cycle. As such, a slower cycle rate (lower GHz) CPU can be faster then a CPU with a higher cycle rate if it can do more instructions per clock cycle. (Athlon vs Pentium 4)
This.
The measure of time can be shown as a sine wave.
Each component of your computer (regardless of clock speed) must cycle in time with the 'wave'. This is called the PLL or 'Phase Lock Loop'.
The clock is directed by a crystal oscillator which (IIRC) runs at either 33MHz or 40MHz. Ultimate clock speeds are determined by the use of 'multipliers' off the crystal.
The most prevalent operating status (i.e., clock cycle) of a microprocessor today is the 'wait state'. CPUs are now so fast they 'wait' for the system memory. Intel with the Core2s developed a more advanced branch predictor to 'forecast' the next memory read during the wait states.
A 'zero wait state' means that your cpu and memory are operating at the same frequency.
When you increase the FSB on an Intel Core2 microprocessor you are simply increasing the speed of the clock cycle therefore your calculations (and branch predictions) from memory are faster.
The i7 (and AMD) are a little different. AMD for example has a base clock of 200MHz (the 'crystal' speed x 5, I imagine). The CPU, the HT and the IMC/NB speeds are all based upon multipliers of the base clock.
I believe (but don't really know) that i7 is quite similar.