I have an i7 4790k and when i built my rig i used the Stock Cooler for like 4 months., i used to get 45-53c idle and would get 60-67c while playing games.as soon as i could afford a cooler i bought hyper 212 evo., now i get 30c idle and 45-55c temps while demanding playing games.
you can reduce heat by:
1. ) underclocking your CPU by lowering the CPU voltage., your CPU is likely using 1.28/1.3 as Default with 4.4ghz turbo boost.
2. )underclocking your CPU without editing BIOs settingsGOING INTO CONTROL PANEL IN WINDOWS 7(should be somewhat the same on windows 8/10) :>power option>change plan settings >change advanced power settings > Processor power management ., Then reduce min/max of CPU and this will use way less CPU voltage.
3. ) Better Air flow., 2-4 Case fans moving air in and out with drop temps on your CPU like 5-8c even with the stock cooler
Ofc Underclocking your CPU reduces Performance So its best you get a better cooler AND case fans for the i7 4790k., both for less noise(i will never for that jet engine cooler) and for better temps.
Good Luck, 😛