PC Watch, a Japanese computer hardware website, acquired at least one Skylake i7-6700K and removed the heatspreader. With access to the bare die, they took some photos and tested a few thermal compound replacements, which quantifies how good (or bad) Intel's default thermal grease is. As evidenced by the launch of Ivy Bridge and, later, Devil's Canyon, the choice of thermal interface between the die and the lid can make a fairly large difference in temperatures and overclocking.

Image Credit: PC Watch

They chose the vice method for the same reason that Morry chose this method in his i7-4770k delid article last year. This basically uses a slight amount of torque and external pressure or shock to pop the lid off the processor. Despite how it looks, this is considered to be less traumatic than using a razer blade to cut the seal, because human hands are not the most precise instruments and a slight miss could damage the PCB. PC Watch, apparently, needed to use a wrench to get enough torque on the vice, which is transferred to the processor as pressure.

Image Credit: PC Watch

Of course, Intel could always offer enthusiasts with choices in thermal compounds before they put the lid on, which would be safest. How about that, Intel?

Image Credit: PC Watch

With the lid off, PC Watch mentioned that the thermal compound seems to be roughly the same as Devil's Canyon, which is quite good. They also noticed that the PCB is significantly more thin than Haswell, dropping in thickness from about 1.1mm to about 0.8mm. For some benchmarks, they tested it with the stock interface, an aftermarket solution called Prolimatech PK-3, and a liquid metal alloy called Coollaboratory Liquid Pro.

Image Credit: PC Watch

At 4.0 GHz, PK-3 dropped the temperature by about 4 degrees Celsius, while Liquid Metal knocked it down 16 degrees. At 4.6 GHz, PK-3 continued to give a delta of about 4 degrees, while Liquid Metal widened its gap to 20 degrees. It reduced an 88 C temperature to 68 C!

Image Credit: PC Watch

There are obviously limitations to how practical this is. If you were concerned about thermal wear on your die, you probably wouldn't forcibly remove its heatspreader from its PCB to acquire it. That would be like performing surgery on yourself to remove your own appendix, which wasn't inflamed, just in case. Also, from an overclocking standpoint, heat doesn't scale with frequency. Twenty degrees is a huge gap, but even a hundred MHz could eat it up, depending on your die.

It's still interesting for those who try, though.