I don’t have any direct benchmarks. However, from gamers nexus review you can see a stock 7700K is around 7% faster than an overclocked R5 3600;
stub Alongside the 3900X and 3700X that we’re also reviewing, AMD launched its R5 3600 today to the public. We got a production sample of one of the R5 3600 CPUs through a third-party and, after seeing its performance, we wanted to focus first on this one for our initial Ryzen 3000 review. We’ve...
www.gamersnexus.net
If you then look at gamers nexus review of the 7700K there is only 1fps difference between the 7700K and the 4790K at stock as they are very similar chips;
For this Intel i7-7700K review, we’ll be looking at thermal challenges, blender rendering performance, gaming performance, and synthetic applications. Among those, FireStrike, TimeSpy, and Cinebench are included. - P6: FPS Benchmarks – 7700K vs. 6700K, 4790K, 2600K
www.gamersnexus.net
Ergo, it’s reasonably safe to assume that the 4790K when overclocked will be faster than a 7700K and therefore faster than the overclocked R5 3600 in games. I can confirm this personally, my housemate has a stock 7700K and gets a lower single and multithreaded score in cinebench than my 4790K at 4.9ghz does. I understand it’s not a direct comparison but it’s hard to find reviewers that have directly compared a 4790K with a 3xxx Ryzen part. This YouTube video is the best I can find and they most trade blows at stock, however the i7 will gain much more from an overclock than the Ryzen part.