Note: I do not take credit for this answer as the information was already posted else-where. I am just spreading it for help.
Source: iPod App ; Intel Channel Guide
Intel Turbo boost;
Automatically runs the CPU faster than its marked frequency (i.e.
2.6GHz -> 2.8 - 3 GHz) if the part is operating under power, temperature, & current specification limits of Thermal Design Power
Thermal design power The thermal design power (TDP), sometimes called
thermal design point, refers to the maximum amount of power the
cooling system in a computer is required to dissipate. The TDP is
typically not the most power the chip could ever draw, such as by a
power virus, but rather the maximum power that it would draw when
running "real applications". This ensures the computer will be able to
handle essentially all applications without exceeding its thermal
envelope, or requiring a cooling system for the maximum theoretical
power (which would cost more but in favor of extra headroom for
In some cases the TDP has been underestimated such that in real
applications (typically strenuous, such as video encoding or games)
the CPU has exceeded the TDP. In this case, the CPU will either cause
a system failure (a "therm-trip") or throttle its speed down. Most
modern CPUs will only cause a therm-trip on a catastrophic cooling
failure such as a stuck fan or a loose heatsink.
For example, a laptop's CPU cooling system may be designed for a 20
watt TDP, which means that it can dissipate up to 20 watts of heat
without exceeding the maximum junction temperature for the computer
chip. It can do this using an active cooling method such as a fan or
any of the three passive cooling methods, convection, thermal
radiation or conduction. Typically, a combination of methods is used.
Since safety margins and the definition of what constitutes a real
application vary among manufacturers, TDP values between different
manufacturers cannot be accurately compared. While a processor with a
TDP of 100 W will almost certainly use more power at full load than a
processor with a 10 W TDP, it may or may not use more power than a
processor from a different manufacturer that has a 90 W TDP.
Additionally, TDPs are often specified for families of processors,
with the low-end models usually using significantly less power than
those at the high end of the family.
The dynamic power consumed by a switching circuit is approximately
proportional to the square of the voltage:
(where C is capacitance, f is frequency and V is voltage).