[mosi]

My new B3 stepping M Pro seems to fail at increasing the vcore above 1.5V regardless of the additional turbo voltage setting. Voltage always stays round 1.5, even if it should be 1.55 or something according to EFI.

Is this a technical limit by the board design or am I doing something wrong?

 

[MIKEVALL]

''Core Voltage - Not recommended too exceed 1.38v, doing so could kill the CPU, we therefor recommend a range of 1.325-1.350v if overclocking.''

http://www.overclock.net/intel-cpus/911402-sandybridge-take-note.html

 

[nagle3092]

Make sure Load line calibration is Disabled. It adds alot of volts on this board. Also make sure you have the offset manually set as well as the Additional turbo voltage set. If left on auto they will just keep pumping voltage into your chip.

 

[mosi]

Aww geez, never post before breakfast.. brain was still off

Don't worry, I've went on as per this excellent guide and hit this ceiling voltage somewhere in the process. Temps were sub 70°C so things were borderline okay with that voltage.
Settings were as follows:

Offset Mode Sign: +
CPU Offset Voltage: 0.005
Additional Turbo Voltage (ATV): various settings
LLC: enabled

and voltage on Prime blend did never exceed 1.5v regardless of the ATV setting. It should've been higher from the setting but it wasn't.