Intel Turbo Boost
Intel Turbo Boost is a technology implemented by Intel in their Core i5 and Core i7 CPUs, which allows CPU performance to be dynamically increased on demand. It is activated when the operating system requests the highest performance state of the processor.
- When the processor is operating below its thermal and electrical limits and the user's workload demands additional performance, the processor clock frequency will dynamically increase by 133 MHz on short and regular intervals until the upper limit is met or the maximum possible upside for the number of active cores is reached. Conversely, when any of the limits are reached or exceeded, the processor frequency will automatically decrease by 133 MHz until the processor is again operating within its limits.
Example (Core i7-720QM)
A example from the table at Core i7 microprocessors:
Turbo Mode of 1/1/6/9 (This means @ 4/3/2/1 cores operation, each is a multiplier of 133MHz. So in simple terms, +133MHz/+133MHz/+798MHz/+1197MHz)
This means, when the operating system does not use all (4) cores of the processor, but i.e. only 2, the processor is running at +798 MHz (6*133) faster than its base speed. (For this i7-720QM example the base speed is 1.6GHz, so when only 2 cores are needed, the processor can run at up to 2.398GHz).