What is clocking

What is clocking?

Answer:

The CPU works on two frequencies: An internal and an external.
The external clock frequency (the bus frequency) is the speed between the CPU and RAM. In the Pentium CPU's it is actually the speed between L1 and L2 cache. In the Pentium II it is the speed between L2 cache and RAM.

* The internal clock frequency is the speed inside the CPU, that is between L1 cache and the various CPU registers.
For practical reasons you let these two frequencies depend on each other. In practice you choose a given bus frequency (between 60 and 100 MHz) and double it up a number of times (between 1½ and 5). The latter frequency become the CPU internal work frequency.
Here I show a number of theoretical CPU frequencies, resulting form different clock doublings: Many of these frequencies will actually never be used, but they are possible because of the system structure:

Bus frequencies	Clock doubling factors	Resulting CPU frequencies
60 MHz	1?, 2, 2?, 3, 3?, 4, 4?, 5	90 MHz, 100 MHz, 120 MHz
66 MHz		133 MHz, 150 MHz, 166 MHz,
75 MHz		180 MHz, 200 MHz, 210 MHz,
83 MHz		225 MHz, 233 MHz, 240 MHz,
100 MHz		250 MHz, 262 MHz, 266 MHz,
		290 MHz, 300 MHz, 333 MHz,
		350 MHz, 375 MHz, 415 MHz,
		450 MHz, 500 MHz

Note an important point: The CPU frequency is the result of the the bus frequency multiplied with a factor. If you increase the bus frequency, it affects the CPU frequency, which is also increased.
Look here at a page from the manual to a ASUS P2L97 motherboard. It has a clear instruction about how to set the the two values (bus frequency and clock factor).