A few days ago, my computer started feeling very slow, and looking a CPU usage, I saw that even the simplest processes required a lot of CPU.
As far as I can tell, it's because the core are all down-clocked to 800Mhz, and won't up-clock again when it's needed.
$ cat /proc/cpuinfo | grep MHz
cpu MHz : 800.000
cpu MHz : 800.000
cpu MHz : 800.000
cpu MHz : 800.000
As a test, I then start up BOINC, to load all my cores to the max, using htop, I see all cores running at > 95%.
My cpu scaling settings:
$ for governor in $(ls /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor); do cat $governor; done
ondemand
ondemand
ondemand
ondemand
With 'ondemand, I expect the core to clock up, and go to full power, but a watch
shows them steady on 800.
To get better performance, I need to manually force it:
sudo bash -c 'for governor in $(ls /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor); do
echo"performance" > $governor;
done'
Whch immediately changes the frequency to:
$ cat /proc/cpuinfo | grep MHz
cpu MHz : 2701.000
cpu MHz : 2701.000
cpu MHz : 2701.000
cpu MHz : 2701.000
stress
to simulate cpu load.