I cant really tell, I didnt use the H100i on the 9900k, from what I have read and heard the 9900k @5ghz is just hotter than the 4790k. But the Ryujin 240 is set to be controlled by the bios, so its just doin its thing.
If I had to do Over, I wouldnt upgrade yet. 4790k is still kicking butt and not caring to take names. I just bought a Corsair 760T and rebuilt the 4790k