Use OCCT instead. Also, Prime95 sometimes has issue with new hardware. Also, from personal experience, unless you are willing to make a custom water loop, or spend 300+ on a high quality AIO (friend uses this Swiftech H320 X2 Prestige), I would stick with High-End Air (Like Noctua for example). Unless you are going for the looks, which is perfectly understandable.
I will definitely suggest to anyone willing to put in the work, custom loops are the shit. Extremely good looking and the performance is amazing. And to be honest, not that hard to do.
The H100 V2 should have no issues running any Kaby Lake CPU, im using one to cool my 6700k that is clocked at 4.7ghz, yes they do have issues but they are cheap and easy to install. While I agree there are better CLC options and an open loop is the best choice, but they are a lot more money. I am using an EK Predator 360 to cool my 5820k in my main system and they are a much better cooler, but an extra $150-$200 compared to a corsair unit