Out of the retail box and installed into any Z170 motherboard the Intel Core i7-6700K is capable of hitting 4.2 GHz by default thanks to the Intel Turbo Boost 2.0 as shown above.
We overclocked the Intel Core i7-6700K processor by simply increasing the multiplier and raising the core voltage on the processor when needed. By just raising the multiplier we were able to get to 4.6 GHz at 1.350V on the core before the system would crash in very CPU intensive benchmarks or tasks. For example our 1080p Handbrake encode would lock up at 90-95% at 4.7 GHz at 1.5V, which is the highest we felt comfortable taking this processor as temperatures would reach 98C even with the Corsair H105 water cooler installed.
With the Intel Core i7-6700K processor running 4.6GHz we were able to score 1013 on the CPU test in Cinebench. We got a score of 931 stock, so this is a nice 8.8% performance gain from this 600MHz clock frequency boost over the base clock that equates to a 15% overclock. All of the performance charts in the review show the Intel Core i7-6700K at both stock and overclocked (4.6GHz), so please reference those in the pages ahead to see how the chip performs in a wider variety of benchmarks.
With the Intel Core i7-6700K running at 4.6 GHz with 1.35V to the core we hit 83C on the Corsair Hydro Series H105 CPU Water Cooler that we were using on the test bench.
After talking to Intel and ASUS about our overclock they urged us to overclock with a discrete video card in our system as that should help remove some of the things running on the CPU to allow for higher frequency gains to be had. We found that we could get 4.7 GHz stable with a discrete video card in the system, but needed to set the core voltage to 1.45V.
In Handbrake we were able finish our 1080p workload on the Intel Core i7-6700K 8.9% faster with this overclock than at stock speeds, so it looks like you can get just shy of a 10% performance gain by overclocking this particular processor. No two processors are identical though, so just use these results as a rough estimate of what to expect.
Running the Intel Core i7-6700K processor at 4.7 GHz was nice, but when running a heavy CPU load the temperatures were in the low 90C range and peaked at 96C. This is a little warmer than we’d want to run a 24/7 overclock on a water cooled system, but shows that an All-In-One water cooler like the Corsair Hydro H105 is able to keep Intel’s new flagship cool and get you in the 4.6 to 4.7 GHz range without experiencing any throttling.
Let’s see how the Intel Core i7-6700K Skylake processor performs at both stock speeds and at 4.6GHz!