TechSpot published Intel Core i7-4790K Devils Canyon
A quote from the article:
After last month's underwhelming Haswell refresh, Intel says overclockers can rejoice over the newest revision of its fourth-generation Core processors, codenamed Devil's Canyon, which actually promises a few improvements on the CPU side of things including updated packaging materials, more capacitors for smoother power deliver, as well as a 'Next Generation Polymer Thermal Interface Material' (NGPTIM).Intel Core i7-4790K Devils Canyon Review @ Techspot
If you recall, Intel moved the voltage regulator on-die with Haswell and this caused problems for overclockers by creating an additional hot spot on the chip. Moreover, the company never changed the thermal interface material (TIM) from Ivy Bridge, which was believed to be a downgrade from Sandy Bridge's and led to Ivy Bridge and Haswell parts to running hotter than older Sandy Bridge ones.