Dear all,
I just monitored the booting process on then console and have seen there two errors

modprobe: FATAL: Module cpufreq_powersave not found in directory /lib/modules/4.14.232-ipfire
modprobe: FATAL: Module cpufreq_userspace not found in directory /lib/modules/4.14.232-ipfire

Also O have seen that my fanless system is quit hot on the surface.
However I can see the cpu_freq diagrams in the gui.

What can I do to slow down the CPU in order to save energy.

Not sure if this is the best solution, but I have the following in file: /etc/sysconfig/rc.local

#Set the CPU frequency scaling governor for all cores to powersave
cpufreq-set -r -g powersave

Thanks’ I will try it out

Strange. cpufreq_powersave is compiled into the kernel. But a modprobe cpufreq_powersave should not complain about the missing module. (At my system it output no error)

But also keep in mind that some cpu’s doesn’t support some governor. e.g. intel-pstate based cpu’s will not work on on_demand. We set performance in this case because powersave will clock some cpu’s really slow (200MHz) and are often unuseable in this mode.

At my tests also the power consumption was unchanged or even higher because the powermanagement works better if you ran a task fast as possible and then go to sleep.