What was your Ambient temperature? (Standard or "normal" is 22°C or 72°F.)
What test(s) were you running?
What cooling are you running?
Maximum Core temperature was 71°C (Core #1) with all Cores at 4.5 GHz / 1.280 Core voltage / 61 Watts. The i7 7700K is a 91 Watt processor, so that means you were only running at 67% Thermal Design Power (TDP) which is just 67% or 2/3 workload.
Here's the operating range for Core temperature:
Core temperatures above 85°C aren't recommended.
Core temperatures increase and decrease with Ambient temperature.
Although 71°C is certainly OK for now, without knowing your ambient temperature or cooling solution, we can still predict that if you ran a...