See my post #12. It's not Microsoft but Intel rather. Just download intel power gadget, max the CPU with handbrake transcoding and you should see that the whole 15 W TDP is gobbled up by CPU alone. Throw in the GPU then you've got the power throttling mess.
Given the issue causing this as you have described, the hardware (Intel) design has limitations on load that impacts performance. Its hard for me to understand how this could not have been identified during product testing prior to releasing the chipset. Intel must have rolled the dice on the type i7 users knowing the potential risks caused by heavy load.