3 ms·
> This eliminates the need for an on-battery or plugged-in performance mode because it changes frequencies so fast, you're no longer losing performance by waiti
by vbezhenar 5y ago
> This eliminates the need for an on-battery or plugged-in performance mode because it changes frequencies so fast, you're no longer losing performance by waiting for the software to speed up the cpu. So you can keep it on all the time.
Here's my /etc/rc.d/rc.local script:
#!/bin/sh
for policy in /sys/devices/system/cpu/cpufreq/policy*
do
echo "power" > "$policy"/energy_performance_preference
done
Here's available preferences:
$ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences
default performance balance_performance balance_power power
Basically I can choose between "performance" and "power" (low performance) modes. I'm choosing power, so my fans are silent. And they're silent indeed, no matter the load.
- Hello71 5y agoecho power | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
- alexeldeib 5y agofor no additional output, sponge over tee! sponge is useful in some cases where redirecting output is annoying, and it can construct pipelines reading/writing from the same file. Found that one way later than I'd care to admit. I use tee $FILE > /dev/null <EOF quite often in some situations where redirects get ugly, and sponge is a nice util to tidy up the invocation.
- avel 5y agoUseful, thank you. It appears that this is the setting the Ubuntu / Gnome's "Power -> Power mode" setting changes as well.