Guru 3D has a review of the new i5-8600k: http://www.guru3d.com/articles_pages/intel_core_i5_8600k_processor_review,1.html. As you would expect, single core performance and IPC appear to be almost identical to the 8700k.  Overclocking potential is very good and performance in games mostly matches the 8700k. All this for 100 UK pounds less than the 8700k. The new gaming king?

A comprehensive review can be found also here:

http://www.eurogamer.net/articles/digitalfoundry-2017-intel-coffee-lake-s-core-i5-8400-i5-8600k-review

5 hours ago, Vali said:

A comprehensive review can be found also here:

http://www.eurogamer.net/articles/digitalfoundry-2017-intel-coffee-lake-s-core-i5-8400-i5-8600k-review

It just shows the variability of reviews. In the only common game tested, Rise of the Tomb Raider, Guru 3D managed to get the 8600k to match the 8700k in an identical test at stock speeds. In the Eurogamer test it was 10 FPS slower.

Once the price of suitable motherboards drops, the 8400 also looks like being an excellent budget gaming CPU.

That's the problem with benchmarks in one bench on Far Cry Ultra settings the 7700k topped all the latest CPU`s, 

I found interesting also this review, for 8400.

 

Would be interested to see comparison of the 8600k vs the 7700k. More power per thread on the 7700k and only a tad more expensive.