reducing power consumption of proxmox nodes

I noticed the other day that my proxmox nodes are running at max turbo frequency all the time. Even when there is virtually zero activity, the 8700 and 7700k are sitting at 4.2ghz+ on all cores. The little x270 stays locked at 3.4ghz on its two cores. Since these servers idle a huge amount, they really don’t need to be at max turbo constantly. I saw it recommended on the Proxmox forum to change the cpu governor. Does it work?

let’s measure the power consumption

First, we need to install linux-cpupower

apt install linux-cpupower

Then we can run turbostat to get a rough idea:

turbostat –quiet –show Package,Busy%,Bzy_MHz,PkgTmp,PkgWatt,CoreTmp –interval 5

Here’s what mine look like with the default governor:

i7 8700:

i7 7700k:

i5 7200u:

let’s change the cpu governor

Changing the governor is pretty easy:

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

Now let’s see how the cpu frequency and power consumption have changed:

i7 8700:

i7 7700k:

i5 7200u:

Pretty nice reductions! Haven’t noticed any changes in performance for my normal services, since the turbo just ramps back up as expected when you apply a load.

You can revert the change back to default easily:

echo “performance” | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

Happy homelabbing!


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