x64 build: Power consumption during idle states

Since I’m trying to setup a x64-based 24/7 media- and cloud-storage-server, low power consumption is of upmost importance to me.

I’ve found that my system draws about 1W less power when running Windows 10 as opposed to Ubuntu LTS 18.04. I’m curious about how power consumption during standby differs under DietPi compared to a regular Ubuntu install. Where should DietPi fall in this comparison?

Also, can I expect external USB drives to stay in standby-mode when not in use?


Power consumption depends on kernel/CPU driver support, this is out of our control, however, most CPU’s are supported well in the default 4.9 kernel, and should offer ondemand CPU gov.

As DietPi is minimal, and, only installs what you need, you should also see a overall reduction in power consumption, compared to Ubuntu etc, which has lots of background processes.

You can tweak the CPU govs in dietpi-config > performance options.

In regards to external HDD spin down:

  • DietPi sets a 10minute idle spin down for supported drives on /dev/sda via /etc/hdparm.conf
  • You can add more drives, or tweak it, at the end of the config file /etc/hdparm.conf

Since the new Debian Buster rc1 release is finally able to boot on my UEFI machine, I was able to do some more testing.

When running the latest OpenMediaVault software (which is based on Debian as well) on this device, the CPU properly throttles during idle and I get pretty nice power consumption values at around 2,5W.

On a minimal install of DietPi however, I can only select from either “performance” or “powersave” as possible CPU Governors. Shouldn’t there be an “on demand” option as well, so that the CPU can enter low powered idle modes when not in use?

As Fourdee mentioned above, it depends on the kernel and CPU features it detects.

Please paste (from both systems):

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
dpkg -l linux-image*