How to overclock non K Haswell with max turbo coefficient ...?

Hello,

I am surprised to find some XTU scores where the max turbo coefficient for Haswell (e.g. 4670 minicoopers`s XTU score: 1055 marks with a Core i5 4670) seems to be the value which is normally only achieved with 1 core.

I think this is just a diaplay "bug" from cpu-z not showing the number of active cores, hence x 38 is displayed with 4c/4t while only 1 core is active ; I suppose C3 mode is activated in the bios?

Similarly, XTU shows 4.15 Ghz max frequency, corresponding to 38 x bclk, but only when 1 core is active as it says this time.

When the XTU benchmark runs on 4 cores, the coefficient drops to x36 hence the frequency only equals 36 x bclk = 3.935 Ghz ...?

If someone can confirm, I 'd be happy.

Also, is there any gain to run with C3 activated? I tried long ago but never noticed any gain, but maybe things have changed.

Or if there is a way to unlock the max turbo for 4 cores to the value obtained with 1 core, please share

Thanks.

Cheers