How Intel Turbo Boost Works:
Turbo Boost is a dynamic feature. There is no set-in-stone speed which the Core i5 or i7 processor will reach when in Turbo Boost. Turbo Boost operates in 133Mhz increments and will scale up until it either reaches the maximum Turbo Boost allowed (which is determined by the model of processor) or the processor comes close to its maximum TDP.
Turbo Boost will only kick-in when one core is being stressed, since this will
mean increasing power use for this one core, power which is taken away from the
Use therefore a stress-test like Prime95 that can be run on one single core.
Turbo Boost can only be obtained when just one core is being stressed and the
CPU does not get too hot.
Turbo is autonomous. Don't expect it to keep maximum speed for any length
of time. The point is to optimize resources in terms of energy and speed depending
on the application. The algorithms involved are built into the CPU and cannot
Turbo Boost might kick in, just not the way you might expect it to look like.
Sometimes it will boost for less than a second for a single set of instructions.
If you want it to always stay high, the only way is to
disable Turbo and overclock the processor from the BIOS (not recommended).
Use CPU-Z to see Turbo Boost
under the Clocks section in "Core Speed".