Hacker News Reader

Comment by Timja | Hacker News Reader

A little update:

This makes the noise even louder:

    echo performance | tee /sys/devices/system/cpu/cpu[0-9]*/cpufreq/scaling_governor

This brings it back to the original, already too annoying, level:

    echo powersave | tee /sys/devices/system/cpu/cpu[0-9]*/cpufreq/scaling_governor

So it seems somehow related to the CPUs.

View on HN

If that makes a difference you can also try to fiddle with min/max cpu frequencies.

I use powersave capping the max freq unless I have something big to compile etc (just to help make sure the fans won't kick in, in my case, but it might help)

Just write whatever frequency you want to /sys/devices/system/cpu/cpu[0-9]*/cpufreq/scaling_max_freq and scaling_min_freq

The lower I set scaling_max_freq, the lower is the noise.

The lowest I can set it to seems to be 40000. I can still hear noise, depending on what the laptop does.

As simple command to create noise is:

    while true; do echo -n $RANDOM; done

It makes noise even when the terminal is not visible.

I guess I would lose about 90% of performance if I permantently set scaling_max_freq to 40000?

Yes, in theory the CPU would be forbidden to run at higher frequencies, so I'm not sure how viable 40MHz would be! I'm actually impressed you can go this low (limits are written in cpuinfo_min_freq and cpuinfo_max_freq in the same directory), my old cpu min is 400MHz. At this frequency stuff like firefox really start to struggle, I've never kept it that low for long.

I normally scale down to about 1GHz without much visible performance impact except for compiling, and that is enough for fan to not kick in randomly everytime a web page has some somewhat heavy js or whatever it is I'm doing, but obviously you're looking at a different beast.

Reply on news.ycombinator.com