I posted about this over here, but that has not gained much traction, so I figured that this might be a better place to ask. The full details are in the Reddit post, in case I forget something here, but essentially, I am having trouble with what appears to be a CPU TDP throttle restricting my 3920xm overclock when the package power reaches 55W.
My specs are:
System: M17x R4
GPU: GTX 980m
RAM: 16GB (4x4GB) DDR3 1333MHz
OS: Windows 8.1 64-bit (MBR/legacy boot with Optimus)
BIOS: A11 Unlocked
No matter what multiplier I set in the BIOS or Intel XTU for any combination of 1, 2, 3, or 4 cores active (currently trying 42x for all) my CPU still throttles back to 3.6GHz under a benchmark. Moderate loads of around 50% see a max ratio of 40x~41x but still not meeting the overclock I set. Under a full load at 3.6GHz my CPU is only reaching about 88º C with both an upgraded CPU fan and a repaste, so I don't think that thermal throttling is causing this trouble at the moment.
ThrottleStop lights up the "TDP Throttle" indicator when this happens, and looking under TPL shows that ThrottleStop is reading a Turbo Boost power limit of just 55W (which is Intel's factory max). I do have "Turbo PWR Limit MSR Lock" disabled in my BIOS, and current limits maxed. To be fair, though, this BIOS is still very unfamiliar and difficult to navigate for me, so I could very well have incorrectly adjusted some values.
Is there a way to force the (Turbo) TDP limit higher than 55W? Is my system actually capable of sending more power than this to the CPU? Is there maybe something wrong with my CPU that causes it to ignore my BIOS settings?