das_stig,
Although you're correct that 74°C is well within spec's, respectfully, Intel's spec for "Throttle" temperature (Tjunction) for the i7 7700K is not 90°C; it's 100°C:
Intel® Core™ i7-7700K Processor -
https://ark.intel.com/products/97129/Intel-Core-i7-7700K-Processor-8M-Cache-up-to-4_50-GHz
Ahmed21,
Here's the operating range for Core temperature:
Core temperatures above 85°C aren't recommended.
Core temperatures increase and decrease with Ambient temperature.
Idle temperatures below 25°C are generally due to Ambient temperatures below 22°C.
Q: What is your ambient (room) temperature?
Highest Core temperatures occur during stress tests, rendering or transcoding, but are lower during less processor intensive workloads such as applications and gaming. Core temperatures can vary greatly among games due to differences between CPU and GPU workloads. "Normal" gaming temperatures are about mid 50's to mid 60's.
Your gaming Core temperatures are mid 70's because the 7700K is difficult to cool. Not to pop your bubble, but the Corsair H60 is not a very capable cooler, and is only on par with mid-range air coolers.
Further, if you live in the Northern hemisphere it's the middle of winter, so your daytime indoor Ambient temperature is most likely below "normal", which is 22°C or 72°F. Since Core temperatures increase with Ambient temperature, as winter changes to summer you may find that your Core temperatures might exceed 80°C. If that happens, you might want to look into a better cooling solution.
Guys, if you'd like to get yourself up to speed on this topic, then read this:
Intel Temperature Guide -
http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html
CT