If you want to maintain all power-saving technologies on Gigabyte GA-P55-UD6ou have to give up changing the processor Vcore and thus limit the overclocking. With static Turbo Boost and nominal processor Vcore we had to stop at 166 MHz base clock, which produced the resulting CPU frequency of 3.65 GHz.
However, this time both: the CPU multiplier as well as Vcore were lowered in idle mode.
If we are talking about dynamic Turbo Boost that can increase the processor clock frequency multiplier to 26x in case only one of the processor cores is loaded with work, then you will have to lower the base frequency even more: to 154 MHz. But in this case the CPU clock frequency will indeed reach 4 GHz bar.
However, if all cores are loaded to their maximum by multi-threaded calculations, then the maximum CPU overclocking will stall at 3.39 GHz.
Just as in the previous case, when the processor is not heavily loaded, all Intel processor power-saving technologies remain up and running.
Despite everything, our CPU overclocking experiments on Gigabyte GA-P55-UD6 mainboard were a success. Of course, the board’s inability to keep processor power-saving technologies up and running, when the CPU core voltage is increased, does tie our hands a little bit. Asus mainboard allows us to keep the voltage at its nominal level, increase or lower it, but if there is no operational load, it will lower not only the multiplier but also the CPU core voltage. On Gigabyte mainboard power-saving will work properly only in case the CPU Vcore remains nominal. However, the maximum overclocking for our Intel Core i7-860 processor we managed to achieve on Gigabyte mainboard was just as good as on Asus, which is a great result.