I have this issue with my h100i v1 maybe it's the h100i that's the issue but don't know. Anyway I bought this
thermal paste to actualy replace the bad thermal paste on my 980ti HOF. It works bought temps down from 80-84C to 75C max and real games under 70C.
i decided to do my cpu as well. Was running Arctic silver 5. i still had left so might as well do it. It should be better than arctic silver 5 but funny on my cpu even on stock clocks it does worse than arctic silver 5. When I had arctic silver 5 on was reaching 80C on cinebench overclocked to 4.6ghz then I replaced it with cooler master mastergel maker nano and got temps of 100C on stock clocks. So don't know why it will be worse than Arctic silver. I also tried different application methods (x, spread, rice size) nothing worked. I thought my h100i was faulty then I went back to Arctic silver 5 and was just fine again. 80C on cinebench overclocked.
So what can be the issue? I've asked many places and phoned many shops, suppliers, etc and no one can help. I even asked cooler master why it's not working and they told me I must check if everything is nice and tight and the pump and fans is working. I did same for both Arctic silver 5 and Mastergel maker nano and every time Arctic silver wins by a mile.
Seeing as it worked on my GPU I don't think there might be something wrong with the thermal paste. On my gpu the Arctic silver was a clear looser as max temps in stress test was still 80-84C and in games easy to reach 75-80C now I only get 70C and sometimes as low as 64C max. So mby the looks thermal paste is working just fine or maybe not. We must remember the gpu is directly on the die where cpu is on a headspreader.