I've struggled with this exact issue for over the past 2 years on my Dell Precision M6500 and M6600 laptops. It's been wildly frustrating.
M6500 - 940XM, 32G 1333
M6600 - 2960XM, 32G 1333
It's stupifying to watch my M6500 thermal trip at 100C with the fan's spinning at...