Question CPU spiking to 100% usage

Sep 27, 2019
So, two problems which I suspect are related:

During a stress test using Prime95, the computer shuts down. CPU temperatures barely reached 70°C before the shutdown happened.

CPU spikes to near-100% which causes stuttering. I've mainly had it happen in video games since that's mostly what I do on my computer. Again, core temps don't reach anywhere near maximum levels when the computer stutters.

CPU: Intel Core i7 6700K
Mobo: MSI H110M PRO-VD
GPU: 980 Ti
PSU: Corsair 600W, 80Plus certified.
All of these components are three years old.

I removed the case lid and created airflow through my room on a chilly night. Stuttering in-game was still present.

My mobo is cheap. Since throttling is present, could it be the problem? I think it's more likely to fail than the PSU, since the PSU is supposed to be high quality.


Mar 13, 2017
Stuttering will be the same if you suffer from cpu bottleneck or the vrms are overheating. Two different issues with the same symptom. first delineate which one is causing the stutter. I wonder which game bottleneck the 6700k that way?
I'd check all BIOS settings, perhaps there are protective features engaged to shutdown at certain CPU temps or power levels, either of which could be hit in Prime95/small FFTs...

Certainly a rig powering itself off is indicative of such behavior, or, a very weak PSU...

Let's fix that first, and see where we are at afterwards...

(What all-core clock speeds are noted on HWMonitor during Prime95?)