Hexus posted a review on the Intel Core i7-7700K overclocked to beyond 7GHz
A quote from the article:
Yes, hyperthreading and cores were disabled, voltage set high, and lashings of LN2 applied. We still await the official launch of the Kaby Lake desktop processors from Intel. Easing the waiting pain, HEXUS thoroughly tested an early 14nm+ Core i7-7700K sample from Intel early this month. Unfortunately, the improvements evident over Skylake processors left quite a few readers underwhelmed. On a positive note we noted the potential headroom for overclocking thanks to the reworking of the 14nm process. In tests our sample clocked up to 4.85GHz on air, stable and considered suitable for long-term usage.Intel Core i7-7700K overclocked to beyond 7GHz @ Hexus