# FreeBSD 13.0 and CPU power management



## jbo (Sep 16, 2021)

Freshly installed FreeBSD 13.0 on a Lenovo Thinkpad P2000 it would seem like the CPU frequency is begin scaled down automatically if the load is low.
Based on my notes from a couple of years ago, I was using sysutils/powedxx back then with some basic configuration in /etc/rc.conf to manage CPU power levels / frequency.

I'd like to understand what I'm experiencing on my fresh FreeBSD 13.0 installation. Is this a feature that is now part of FreeBSD out-of-the-box? Or is this a hardware/firmware based CPU frequency scaling? Or is `powerd` running by default?
Is using sysutils/powerdxx on "modern FreeBSD 13.0 machines" still a thing?


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## diizzy (Sep 16, 2021)

(EDRIVER) frequency control driver not supported: hwpstate_intel0 · Issue #15 · lonkamikaze/powerdxx
					

Hello, I cannot use powerdxx on FreeBSD 14 CURRENT ( cf5d11124 ) on a Lenovo Legion 5i It gives the error: powerd++: (EDRIVER) frequency control driver not supported: hwpstate_intel0 Any hints? Tha...




					github.com


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## jbo (Sep 16, 2021)

How would one go about figuring out whether `hwpstate` is supported on the CPU in question and whether it's actually enabled/running/working?


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## vermaden (Sep 16, 2021)

jbodenmann said:


> Freshly installed FreeBSD 13.0 on a Lenovo Thinkpad P2000 it would seem like the CPU frequency is begin scaled down automatically if the load is low.
> Based on my notes from a couple of years ago, I was using sysutils/powedxx back then with some basic configuration in /etc/rc.conf to manage CPU power levels / frequency.
> 
> I'd like to understand what I'm experiencing on my fresh FreeBSD 13.0 installation. Is this a feature that is now part of FreeBSD out-of-the-box? Or is this a hardware/firmware based CPU frequency scaling? Or is `powerd` running by default?
> Is using sysutils/powerdxx on "modern FreeBSD 13.0 machines" still a thing?


Generally its like that that *powerd(8) *keeps clocks higher while *powerdxx(8) *keeps clocks lower.

One may say that its better to use *powred(8) *when AC is available and *powerdxx(8) *when working on battery.

You may also find some Power Management related tips here:








						The Power to Serve – FreeBSD Power Management
					

This is the motto of the FreeBSD operating system – The Power to Serve – which also greatly fits for the topic of this article. Decade ago (yes time flies) I even made a wallpaper with …




					vermaden.wordpress.com


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