How to reduce electricity consumption

[gusto]

I recently saw this procedure as a way to reduce electricity consumption.
I set it up the way the guy describes it

echo "powersave" | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

It is set from 7:00, see graph.
The CPU increased from 2% to 4%, but the total consumption decreased by 3-4 Watts
Is this setting ok? Doesn't the CPU suffer?

 

[leesteken]

The CPU increased from 2% to 4%, but the total consumption decreased by 3-4 Watts

The CPU runs slower, so it is more busy. Are you measuring power over time? If it uses less power but uses power for longer, then it might not help you or make things worse.

Is this setting ok? Doesn't the CPU suffer?

It's fine for the CPU. You need to measure power usage over time to make sure it helps you.

 

[Dunuin]

Depends on the CPU. With some CPUs the "powersave" governor will limit the CPU to the minimum clock and won't allow it to clock up at all (in which case the "schedutil" governor might be better). With other CPUs it just tells the CPU to clock down more often but it still allows it too clock up when needed.

And best way to save electricity of cause is to only run a PVE server when needed. I for example got another small homeserver that runs the stuff that needs 24/7 availability and the big server only runs on demand when needed. So I can shut the big one down when not at home or while sleeping.

 

[gusto]

It's a home server and it's idle a lot of the time.
CPU is Intel Core i5-10400, MainBoard
If you know of any settings to reduce consumption, I will be grateful

 

[Dunuin]

You can install powertop. Useful to see what's going on (clocks, c states, consumption, cpu time, ...) and it will show you if there is something that can be optimized (link power management, autosuspend, runtime PM, ...).

 

[LnxBil]

And best way to save electricity of cause is to only run a PVE server when needed. I for example got another small homeserver that runs the stuff that needs 24/7 availability and the big server only runs on demand when needed. So I can shut the big one down when not at home or while sleeping.

This. Anything else will not accomplish much.

 

[Jarek Hartman]

If somebody interested in real-life data:

• An idle system with AMD Ryzen 9 3900XT 12-Core Processor, 6 HDDs, 2 SSDs, ..., etc
• As per lscpu, CPU max MHz: 4775.9761, CPU min MHz: 2200.0000
• Default scaling_governor = performance
• Tuned to conservative (using `cpufrequtils`)

Average power consumption dropped down from 112 Watts to 91 Watts:



So pretty substantial difference (18%), without any noticeable performance hit for the workloads I run.

Thank you,
Jarek