How processing speed is changed automatically?

[sr13579]

Assume, we are playing a game and it needs 300 MHz processing speed. As we can see when we start a software or a game the processing speed increases.I have several questions to ask,
1. How a processor knows when to increase the clock speed?
2. And what does 2 GHz processor means?
3. Is it always going to give us 2 GHz or when we need it?
4. Is it possible to teach me these things with 8086 references?
5. How the processing speed is controlled?

 

[ronsimpson]

2 GHz = 2,000 mhz

 

[gophert]

When the cpu has nothing to do, it can start skipping clock cycles to save power. Or a cpu clock speed can be reduced, where the CPU tells the clock to skips pulses.

 

[ronsimpson]

This is a very small computer. It often is used in low power applications. The CPU can run from external crystals or internal. You can see the internal options include 32khz through 16mhz with optional 4x. The computer can select how fast it wants to run. Speed is related to power consumption.

I have used this part in high power mode most of the time but when the off button is pushed the computer goes into slow, low power mode and only looks for the on button.

The computer does not really decide how much power to use. Software some one wrote decides.
In a PC, when there has been no keyboard or mouse movement for 5 minutes the computer might start shutting down pieces that are not needed. In a laptop the speed will be reduced to save battery.