[need expert knowledge]how turbo boost work?

how does turbo boost for Core i7 720QM

the stock clock speed is 1.6Ghz quad core with 4 virtual cores


if 1 core is at 100% load and the other 3 is inactive the speed will be 2.8Ghz


if 2 cores is at 100% load and the other 2 is inactive the speed will be Ghz?


if 3 cores is at 100% load and 1 core is inactive the speed will be Ghz?


if 4 cores is at 100% load the speed will be Ghz?


if 4 cores and 4 virtual cores is at 100% load the speed will be Ghz?

 

The answer to all your questions is 2.8Ghz.Since the maximum turbo boost frequency is 2.8Ghz, even if one core is at 100% that will be the frequency.The inactive cores don't even take part at the process at that moment.

 

2 cores - 2,4GHz
3 cores - 1,73GHz
4 cores - 1,6GHz (or 1,73GHz if Your laptop has an efficient cooling system)
4 cores - 8 threads - 1,6GHz

 

There is no such thing as 100% load in practice (even if Windows' resource monitor shows you so). The most torturing software can maybe keep 90% of a CPU's resources busy. Turboboost kicks in when (i) the OS demands P0 (the highest-performance state) for at least one core and (ii) certain thermal and electrical limits are met (e.g., the T_case temperature must be below a pre-specified number). Note that P0 =/= 100% load.