All tests were performed with the default settings of the motherboard. We used to set the C-states on maximum and we enabled EIST, however we leave those decision to the manufacturer now.
Of course the performance and power consumption depend on the standard tuning. Motherboard manufacturers used to cheat a little by slightly increasing the bClk. We and other review sites did not like this at all and the various manufacturers have therefore changed their ways. As you can see in the graph below the maximum deviation we were able to find is 0.5%. They also no longer cheat with the clock speed of the IGP.
One little trick many manufacturers do use is standardly making the Turbo-mode more aggressive compared to the Intel standard. The maximum Turbo-mode of the 6700K of 4.2 GHz should only be occurring when one core is in usage, according to Intel at least. Most boards however utilize something we call ''aggressive Turbo'', which in contrast to normal Turbo also scales up the clock speed to the maximum value when all cores are in usage. We can clearly see this in the CPU benchmarks on the next page. Of course you're always free to set an aggressive Turbo yourself.
The ASRock is represented by the red bars, while all other motherboards are represented by blue bars.