The Dancop "ICE-Ball" effect on Skylake CPUs is the audible crack when the contact between the CPU die and IHS, and IHS and CPU pot, is lost. The loss of contact is significant for the overclocking capabilities of your processor as the thermal conductivity is reduced to the minimum. Overclockers have been struggling with the "thermal paste crack" problem for a long time, and Skylake doesn't make things easier.
As Skylake requires delidding to achieve the highest frequencies on liquid nitrogen, there are now two problem points for thermal paste (CPU-IHS and IHS-cooler). In a forum thread posted in the Skylake OC sub-forum, German overclocker and current #1 in the world, Dancop shares his findings on the ICE-Ball effect using different thermal pastes. Among the thermal pastes tested are: Innovation Cooling Diamand 7 Carat, Prolimatech PK1 and PK3, Thermal Grizzly Hydronaut and Kryonaut, Junpus DX-1, EK Ecotherm, Gelid GC-Extreme, and Noctua NH-1.
The results are spectacular. The ICE-Ball temperature under load varies between -120°C (Junpus DX-1) to -185 (Thermal Grizzly Kryonaut). That's 65°C difference for minimum load operating temperature! Check the thread for more information and detailed graph!