Checking the Forums on Anandtech, there is user RichUK who managed to get his hands on an early retail version von Intel’s Core i7-7700K Kaby Lake CPU. After having tested this CPU as he got it now delidded the chip, which helped to drastically improve temperatures.
It turns out that after having replace the standard TIM with Liquid Ultra temperatures were about 30° lower. Initially, when the Anandtech Forum user overclocked this CPU to 5 GHz and loaded it with prime95, temperatures shot to 99°C instantly. With the Liquid Ultra in place as TIM the chip was running at a very reasonable 66 degrees.
It’s not new that delidding your CPU to then replace the TIM makes for a big difference in temperatures. It’s been the same with the Core i7-6700K as well as 4790/4770K in the past. But this time it appears that CPU temperatures benefit the most from replacing the thermal interface material. 33° less with the CPU at 5 GHz is simply a massive improvement.
Apparently you might be asking yourself how this chip has been cooled. User RichUK is mentioning that he was using a NZXT Kraken X62 all-in-one water cooler with the fans running at 50% and the pump at 65%. This means cooling was adequate yet not over the top.
When those CPUs are finally out and the NDA is lifted we’re going to run some tests with a delidded i7-7700K as well, since we’re really curious to find out how delidding raises the bar regarding overclocking limits.
Source: Anandtech Forums