After adding these changes, the server consumes 28W on idle instead of 48W.
Make sure all the C-States features are enabled in the motherboard and set the lowest possible state to C10 instead of auto.
Go to your proxmox shell and install powertop
apt install powertop
Now let powertop auto-tune your powersaving settings.
powertop --auto-tune
These settings do not persist after a reboot so we will have to create a service to perform this command on startup.
nano /etc/systemd/system/powertop.service
Now enter the following text.
[Unit]
Description=PowerTOP auto-tuning
[Service]
Type=oneshot
ExecStart=/usr/sbin/powertop --auto-tune
[Install]
WantedBy=multi-user.target
Now hit ctrl + X, followed by Y and enter
Now enable the service.
systemctl enable powertop.service
To change the cpu scaling governor to powersave run the following command.
echo "powersave" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Just as powertop this also does not persist after a reboot.
Open crontab.
crontab -e
Select nano as your editor in case you have to choose one.
At the bottom of the file add:
@reboot echo "powersave" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Now hit ctrl + X, followed by Y and enter