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I believe the CPU on my laptop is damaged. Every time I attempt to launch a CPU intensive task (UHD video playing / python math libraries) my whole system freezes.

I noticed I can avoid this by unplugging the AC and then it seems that the system is capable of running most tasks, albeit a bit slower.

Since I cannot run on battery forever my question is, How can I setup the CPU usage to mimic that of 'on battery' even though I am on AC?

I read elsewhere of a tool name cpufrequtils, but I'm not sure that is the way, since that's something I'm supposed to install and my laptop already can regulate based on battery/ac without any additional utility.

I mean, isn't there some place where I can simply specify the max cpu usage/freq ala Windows Power Management options?

Even if I have to use cpufreq, I still don't know the right % that my system uses on battery, so I can set it up with cpufrequtils.

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    Before I start shooting in the dark, could you try posting the output of cpupower -c all frequency-info (or another tool that can report max, min, and stepping info on the cpu: wiki.archlinux.org/index.php/CPU_frequency_scaling ), and detailed info on your cpu (lscpu or a similar command). I wouldn't be hasty to declare a cpu "damaged"; it is more likely that scaling and/or turbo is misconfigured. You may also find some settings for cpu scaling within /sys/devices/system/cpu. – Schives Jan 5 '17 at 7:16
  • There was some problem related to skylake cpus that freezed under certain circumstances wasn't there? Maybe you should look that up – Gasp0de Jan 5 '17 at 16:03
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You could set your CPU scaling govenor to powersave See link Which runs the CPU at the minimum frequency.

According to the same wiki page you need to load the right cpu frequency driver ie. speedstep-lib for Intel SpeedStep-enabled processors (mostly Atoms and older Pentiums (< 3))

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use TLP and force a "battery" behaviour https://wiki.archlinux.org/index.php/TLP

PS: suggestion: 1. upgrade your BIOS 2. it seems an issue related to high temperature

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Your laptop is probably suffering from temperature issues. The complete freeze is a CPU's safety feature; to check, you can monitor the CPU temperature.

If the laptop is reasonably new, it is likely a design flaw; the designers never calculated it would run at high power for very long times. You can underclock your CPU using powerutils (or cpufrequtils). You can run on battery and see what frequency the CPU is reported working at when at full load, then set that frequency (or you can try increasing it in small steps, if available) as the maximum frequency also on AC power:

hardware limits: 798 MHz - 2.00 GHz
available frequency steps: 798 MHz, 1.06 GHz, 1.33 GHz, 1.60 GHz, 2.00 GHz

For example on battery it runs at 1.06, on AC of course at 2.00; at 2.00 it freezes, and we know that at 1.06 it doesn't; but maybe at 1.60 it wouldn't, and lowering at 1.6GHz would be better than going all the way down to 1.06 "on-battery" frequency.

But otherwise - and to be sure, maybe even if your laptop is new - I think you should have the CPU cooling subsystem checked - fan, heat exchanger and above all the thermal pad. I had your same symptoms on a Dell XPS13 M1330, and it turned out that the thermal pad had sort of desiccated and cracked. The "CPU idle" temperature was higher than it should have been. Replacing the pad solved all the problems without any software twiddling necessary.

Some years later, this time on an Acer laptop, I noticed the CPU overheating (no other symptoms though), and a good compressed air blow on heat exchanger and fan brought the idling temperature 5-10 °C lower.

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