[arch-general] Laptop overheating causes decreased CPU performance until reboot (even after cooling)

[Sean Greenslade]

On Thu, Sep 04, 2014 at 05:14:27PM +0530, Anish Shankar wrote:
> Hi,
> I have a dell 1564 laptop with an i5-M430 cpu, running arch linux. For a
> long while now I've had issues with very degraded CPU performance if my cpu
> temperature is very hot till around ~95 degree Celsius. The problem is that
> the degraded cpu performance stays inspite of cooling down back to 60
> degrees, and even multiple suspend-resume cycles. The only way to reset the
> same is a reboot. I can't seem to track down the cause of this. The cpu
> frequency etc. look normal, all 4 vitual-cpu's are active from cpuinfo.
> 
> top reports nearly 5x increased % cpu usage for process compared to what
> they normally use. Some simple CPU benchmarks (N-Queens) also take
> approximately 5 times longer.

Given that, I would suspect (WAG incoming) that the CPU is scaling back
the clock as an emergency measure. 95 degC is WAAAAY to hot for a CPU to
be. You need to fix that issue first. If the cooling system is not
behaving sensibly, you may need to do some manual overrides:

https://wiki.archlinux.org/index.php/fan_speed_control

--Sean