Conclusion

Default

First of all we’re going to have a closer look at performance differences with standard clock speeds. From our overall performance rating we see that the Core i7-5820K is on average almost 14% quicker than the Core i7-6700K. In this case you need to keep in mind, that the i7-5820K packs six cores and twelve threads, whereas the i7-6700K features four cores and eight threads. Taking the different clock speeds and architectural differences into account, then the i7-5820K should be up to 30% quicker than the i7-6700K, when it comes to multithreaded benchmarks.
Searching for benchmarks with best possible scaling on the i7-5820K we find WinRAR benefitting and running more than 35% faster on this CPU than on the i7-6700K. On the other hand it's interesting to see that with Blackhole's Single Threaded benchmark the i7-6700K pulls away by 35%.
We also had a closer look at power consumption and in idle we notice that our test setup with Core i7-5820K was burning 5% more power than our Skylake test platform. In case of load power consumption the difference was 28%.

4.2 GHz

Overclocking both processors to 4.2 GHz basically makes the Core i7-5820K perform 8% faster and the Core i7-6700K benefits by 7%.
A closer look at power consumption reveals that overclocking these CPUs make for quite a difference. With the Core i7-6700K we see system power consumption rose by than 7% in idle and 8% under load, when comparing with the default power consumption values. In the case of the Core i7-5820K system power consumption goes up by 20%, when the CPU is under full load. In idle the difference 71%.

4.2 GHz DDR4-3000

The default clock speeds of DDR4 in the case of both platforms tested is 2133MHz and therefore running the memory at 3000MHz is quite a boost. Overclocking the system with the Core i7-6700K inside we notice that the performance goes up by 12%. In the case of the Core i7-5820K the difference is 17% on average.
Looking at idle power consumption, the system with Intel Core i7-6700K turns almost 15% more energy into heat, whereas with the i7-5820K consumption goes up by 86%. Under full load the differences are almost 16% in the case of the i7-6700K and 28% for the i7-5820K.

Recommendation

If you're looking for a new CPU for a content creation workstation then the Core i7-5820k is the preferred choice over the i7-6700K. Since most professional applications are capable of making good use of six cores and twelve threads, the i7-5820K is overall faster. Should you be using applications which are limited to four cores and eight threads, then the i7-6700K makes more sense, since it will benefit from the higher clock speeds.

Page 1 - Introduction	Page 8 - Frybench
Page 2 - 3DMark Physics	Page 9 - HWBot Prime
Page 3 - XTU	Page 10 - UCBench
Page 4 - Cinebench	Page 11 - Performance Rating
Page 5 - SiSoft Sandra	Page 12 - Power Consumption
Page 6 - Blackhole	Page 13 - Conclusion
Page 7 - WinRAR