Feminist wroteYou definitely need a better CPU fan, especially if you're OCing (which I dont think you are, but 7700K is usually a pretty common cpu to OC)
I would recommend water cooling just because, but if not, then you'll just need to get a better fan. the H7 49.0 definitely doesn't get the job done. maybe for an i5 lol
????? What? Why would OP go and throw an extra couple hundred dollars to watercool his system JUST for minimal performance gains on a CPU OC at a stable temperature?
No, the H7 49.0 doesn't get the job done because "it's shit" it's because his CPU is a mini oven. If OP wanted to get a CPU fan upgrade, he can throw in an AIO instead of a full system loop.
OP: The i7-7700k is known for it's high temps, OC or not. 65-70c under load is a safe margin for your gaming. Low 80's is the safe area, anything getting above that is when I would start to worry. The main question becomes, what is your CPU at idle? You just woke up, turned on the computer and loaded up your CPU monitoring; do you know what temps you are getting there?
Since you mention that before you were at 65-70c but now hitting 75c at times, makes me think your thermal compound might be the issue. I believe the H7 49 comes with pre-applied thermal compound. It's possible that the heatsink wasn't mounted correctly, which didn't spread the compound properly, or the heatsink has "too much give" meaning it wasn't full tightened, air was able to get in between the heatsink, compound and CPU and now air bubbles were eventually able to form, which is uneven heating and I guess in worst case scenario could have burnt the compound but that's so far off that I wouldn't even think burnt compound would be the issue.
You can either get an AIO such as the Kraken x62 (or any AIO fitting the budget you have for one) or continuing using this, just clean off the old thermal compound, apply new compound, mount it and test it's temperatures.
This is the thermal compound I use. It's thick which I like because I don't like runny or messy compound. Put a dot the size of a pea and tighten your heat sink in a diagonal fashion to spread the compound out evenly.
So, these are the 4 screws for your heatsink. You put a pea size drop of paste. Good. You put your heatsink over it. Good. Now you tighten Screw 1 a little bit, then tighten Screw 4 a little bit. Tighten Screw 2 a little bit, then tighten Screw 3 a little bit. Repeat that until all screws are tight for your heatsink. This spreads the paste out evenly because if you tighten Screw 1 all the way down, then that corner has most of the paste, while now attempting to spread what's left to the other corners.
I get around 40 degrees idle. I will try to remount the thermal compound and see what I get. I do not currently OC but I will soon so I might just upgrade to an AIO.
THANKS for you feedback!