I have an i7-7700k and a Cryorig h7 cooler. I recently have tried overclocking my CPU, and I can get 4.9Ghz with a voltage of 1.45V but the temps are in the low to mid-90s when stressing both the CPU and GPU. Alternatively, I can get 4.8Ghz without changing the voltage and my temps stay mostly in the mid to high 80s. Should I stick with the 4.8Ghz overclock or will the CPU be fine with temps being low to mid-90s?
What are you using to stress test? I'm definitely no expert, but 90* on air at that high voltage seems ok. I wouldn't run it at that temp though, or that voltage. Try to stay under 1.4 and in the lower 80s.
Personally, I don't like my CPU (or GPU) going beyond 80c. So drop the frequency and voltages a tad bit, unless you really need every single kilohertz of that 4.9GHz clock speed. Alternatively, just build a water-block and go all the way to 5.0Ghz.
If I was you though; I'd undervolt / clock it to 4Ghz and run it at 60ish temperature. But then again, I happen to be a 'patient gamer' who is more than happy with 720p @ 60FPS with V-Sync.
Although Throttle temperature is 100°C (212°F) for the i7-7700K, it’s not advisable to run your CPU near its thermal limit. If your hottest Core is near its specified Tj Max Throttle temperature, then your CPU is already too hot.
The consensus among well informed and highly experienced system builders, reviewers and overclockers, is that cooler is better for ultimate stability, performance and longevity. Experts all agree that it's prudent to observe a reasonable thermal margin below Throttle temperature. So regardless of environmental conditions, hardware configurations, software workloads or any other variables ...
Core temperatures above 85°C are not recommended.
Core temperatures below 80°C are ideal.
Core temperatures increase and decrease with ambient temperature. The "standard" for normal ambient (room) temperature is 22°C or 72°F. For every degree you're above normal ambient, so are your Core temperatures.
This prematurely erodes the traces and junctions within the processor's layers and nano-circuits, which will eventually result in blue-screen crashes that become increasingly frequent over time. Here's the maximum recommended Core voltage per Microarchitecture from 14 to 65 nanometers since 2006:
With high-end cooling you might reach the Vcore limit before 85°C. With low-end cooling you’ll reach 85°C before the Vcore limit. Regardless, whichever limit you reach first is where you should stop.
Remember to keep overclocking in perspective. For example, the difference between 4.5 GHz and 4.6 Ghz is less than 2.3%, which has no noticeable impact on overall system performance. It simply isn’t worth pushing your processor beyond recommended Core voltage and Core temperature limits just to squeeze out another 100 MHz.