YaST Power Management - Control Your CPU Energy Usage How To & FAQ

jdmcdaniel3 · June 18, 2011, 4:53pm

In openSUSE 11.4, the control of your CPU energy usage has been moved to the YaST Power Management module. This How To and FAQ Tells you how to install and enable this CPU control module. To begin, you must start the YaST Control Center and enter the root user password as normal. Then, proceed to:

YaST / Software / Software Management

http://thumbnails45.imagebam.com/13709/2794c4137085555.jpg](http://www.imagebam.com/image/2794c4137085555)

In Software Management, lets search on yast2-power:

http://thumbnails30.imagebam.com/13709/c2c95d137085584.jpg](http://www.imagebam.com/image/c2c95d137085584)

Check the yast2-power-management package and select the Accept Button on the bottom right to allow it to be installed. Once the package yast2-power-management has been installed, lets Exit YaST and restart the YaST Control Center again. This will allow the new YaST Power Module to appear, but it is not yet ready to be used. Now, we need to go into the Run Level Services as follows:

YaST / System / System Service (Runlevel)

In the System Services window select the Expert Mode Bullet and then find and select the service pm-profiler:

http://thumbnails22.imagebam.com/13709/ba1099137085574.jpg](http://www.imagebam.com/image/ba1099137085574)

Select the button on the bottom right and Enable the pm-profile Service and answer yes to the added services as requested. Select the button on the bottom left and Start the pm-profiler Servrce. You should get a good start with a 0 error return code. Now select the finish button on the bottom right and allow your selections to be saved. Now, it is time to use the new YaST power module. Please Go To:

YaST / System / Power Management

http://thumbnails45.imagebam.com/13709/c50d81137085567.jpg](http://www.imagebam.com/image/c50d81137085567)

In the YaST Power Management module, you have four selections. They are:

Balanced Low Latency Computing
Low Latency Computing
Powersaving
Default

For Desktop usage, you would most likely use the **Low Latency Computing **while if using a Laptop, the Powersaving settings would make the most sense. The **Balanced Low Latency Computing could be useful when used on a desktop or laptop. ** Default is what you start up as which does have some power savings enabled. On Laptops or any computer where heat is a problem or where high fan speed noise is a problem, you will want to select Powersaving. Once you have made your selection here, just press the Finish button on the bottom right for it to be accepted. I also might suggest you restart your PC just to make sure this setting is being used.

Thank You,

DenverD · June 19, 2011, 1:37pm

On 06/18/2011 05:06 PM, jdmcdaniel3 wrote:
>
> I also might suggest you restart your PC just to make sure this
> setting is being used.

i don’t now remember if i had to restart or not…i think i saw the temp
and fan noise drop with even restarting KDE…

i’ve been using it over a week now with no problems…maybe every once
in a while i have a micro-second of hesitation…which i can live with
to get the drop in fan noise (and electricity bill–in the long run)…

well, the slight lag was more apparent when desktop effects was
enabled…but HEY, mine is not a powerhouse game machine, rather a
little, inexpensive, flea powered, energy sipping Atom (in a Acer Aspire
One)…so give it a try on your portable/mobile…

Thank you James, i owe you a Shiner or two if i ever get to town!!

–
dd
http://is.gd/bpoMD

jdmcdaniel3 · June 19, 2011, 3:43pm

i don’t now remember if i had to restart or not…i think i saw the temp
and fan noise drop with even restarting KDE…

i’ve been using it over a week now with no problems…maybe every once
in a while i have a micro-second of hesitation…which i can live with
to get the drop in fan noise (and electricity bill–in the long run)…

well, the slight lag was more apparent when desktop effects was
enabled…but HEY, mine is not a powerhouse game machine, rather a
little, inexpensive, flea powered, energy sipping Atom (in a Acer Aspire
One)…so give it a try on your portable/mobile…

Thank you James, i owe you a Shiner or two if i ever get to town!!
You are very welcome DenverD. If you search on YaST and Power Management, there was a time when YaST did it all (like at version 10 I think), before it was moved to the Desktop. Now, at least with KDE, CPU speed control has been removed, now back with YaST. I am not sure what it all means, but I would just as soon YaST control it all, then it would work the same for all Desktops.

As always, I welcome all comments made here.

Thank You,

gropiuskalle · June 19, 2011, 4:12pm

CLI-users might want to take a look at the package ‘cpufrequtils’ and its two tools ‘cpufreq-set’ and ‘cpufreq-info’. They are quite easy to use and well documented.

jdmcdaniel3 · June 19, 2011, 4:23pm

CLI-users might want to take a look at the package ‘cpufrequtils’ and its two tools ‘cpufreq-set’ and ‘cpufreq-info’. They are quite easy to use and well documented.
Thanks for your comments gropiuskalle. That does make you wonder if you setup YaST as I describe, how often does it send or set the CPU speed? Particularly if you then use a terminal command to change it. How long might your terminal command stay set if you have activated the YaST Power Management? It might be interesting for someone to test the two together to see the results.

Thank You,

gropiuskalle · June 19, 2011, 4:57pm

Sorry, I use cpufreq-set only for such tasks and do not really want to mess that up - plus I have no idea how the YaST (or any other powermanagement) manage frequencies exactly. It’d be interesting to know whether they overwrite each other or not, though.

Why don’t you try yourself? As I said, it’s quite simple to use the cpufreq-utils, in most cases no presetting is necessary, you can use it ootb.

jdmcdaniel3 · June 19, 2011, 5:02pm

Sorry, I use cpufreq-set only for such tasks and do not really want to mess that up - plus I have no idea how the YaST (or any other powermanagement) manage frequencies exactly. It’d be interesting to know whether they overwrite each other or not., though.

Why don’t you try yourself? As I said, it’s quite simple to use the cpufreq-utils, in most cases no presetting is necessary, you can use it ootb.
Well of course I could try this myself gropiuskalle. Since I am unsure of the outcome, I have determined it is better to delegate such tasks to other younger individuals (such as yourself) possible unaware of the potential pitfalls of doing so. lol!

Thank You,

gropiuskalle · June 19, 2011, 6:10pm

Harr!, we are such sissies, aren’t we? I can assure your cpufreq won’t do any harm.

Anyway, I might take a look into YaSTs management in the next few days (not today, I’m a little busy here).

brunomcl · June 20, 2011, 1:55am

Hi, jmcdaniel,

Thanks for the HT, well done as you usually do

One thing I’m puzzled: I installed oS 11.4 64-bits KDE 4.6.3 in a HP laptop I have here (pavilion dv6232br) and the power management features work, but through the power management module in system-settings. The CPU freq scales (2.000 to 800 GHz), powersave mode when running on battery, etc.

According to Yast Software management, Yast2-power is not installed.

What’s happening? Is this only in KDE4, the other desktops require the yast module?

jdmcdaniel3 · June 20, 2011, 2:03am

Hi, jmcdaniel,

Thanks for the HT, well done as you usually do

One thing I’m puzzled: I installed oS 11.4 64-bits KDE 4.6.3 in a HP laptop I have here (pavilion dv6232br) and the power management features work, but through the power management module in system-settings. The CPU freq scales (2.000 to 800 GHz), powersave mode when running on battery, etc.

According to Yast Software management, Yast2-power is not installed.

What’s happening? Is this only in KDE4, the other desktops require the yast module?
I use KDE all of the time and so I can’t say about any other desktop. And so there is a default power savings setup for you, well, by default, no matter the desktop that is used. You just can’t change it from say KDE. The YaST Power Management module appears to provide either more or less power saving from that default. But of course, if you are happy with the default in your selected desktop, there is no reason to take any other action. For me on a desktop computer, I wanted the highest performance I can get while a Laptop might want even more energy savings. At least with solution, you can have a choice.

Thank You,

brunomcl · June 20, 2011, 2:27am

Well, that’s what puzzled me. I understood that there was no CPU scaling without yast’s power module, among other controls.

I don’t have this module installed, so I don’t know if it is more granular than KDE’s. At least OOTB oS do manage - or at least scale - the cpu freq, besides changing the display settings and enabling/disabling 3D effects. So it seems that for basic power management needs the KDE module is good enough.

Thank you for clarifying the issue.

glistwan · June 21, 2011, 1:45pm

How does the YaST power management integrates with KDE’s power devil ?
What happenes if there are different settings in YaST and in power devil ?
Which settings are prefered ?

Best regards,
Greg

jdmcdaniel3 · June 21, 2011, 11:53pm

How does the YaST power management integrates with KDE’s power devil ?
What happenes if there are different settings in YaST and in power devil ?
Which settings are prefered ?

Best regards,
Greg
In KDE 4.6 and above, there is no attempt to control CPU speed at all. It has been removed completely. This is the reason to need to use the YaST Power Management package for this purpose.

Thank You,

consused · June 22, 2011, 12:31am

This is also my preferred way to control cpu frequency, and it’s independent of the DE. As you say, easy to use and well documented.

Whether KDE or YaST, they just use basic system functions, so nothing has actually moved anywhere.

hank_se · June 24, 2011, 1:31pm

I also use cpufreq on my netbook, intel atom based. Installing the package laptopmode-tools adds the extra feature to make changes persistent. Althoug it has no graphical user interface settings are easily edited under /etc/laptopmode. Now although the ondemand governer does a pretty good job with an atom there’s still some extra time to squeze from the battery by changing it to powersave.

jdmcdaniel3 · July 10, 2011, 10:15pm

For anyone reading this thread, but wanting to use the cpu frequencies utilities instead, check out my blog on the subject here:

C.F.U. - CPU Frequency Utilitiy - Version 1.10 - For use with the cpufrequtils package - Blogs - openSUSE Forums

This is about a bash script file called C.F.U. that uses cpufreq-set and cpufreq-info if they are installed, please check it out.

Thank You,

tweakhound · July 10, 2011, 11:48pm

Great thread, real good info here!
jdmcdaniel3, thanks for CFU

jdmcdaniel3 · July 10, 2011, 11:51pm

Great thread, real good info here!
jdmcdaniel3, thanks for CFU

I always appreciate the kind words tweakhound!

Thank You,

robopensuse · July 16, 2011, 1:23pm

Trouble with pm-profiler, it seems to depend on the deprecated haldaemon; I wouldn’t put too much work in on managing profiles with pm-profiler

# pm-profiler -l
PROFILE=low_latency
Error org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Hal was not provided by any .service files
CPUFREQ_GOVERNOR=
SATA_ALPM=
DIRTY_WRITEBACK_CENTISECS=300
READ_AHEAD_KB=128
Error org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Hal was not provided by any .service files
CPUFREQ_GOVERNOR=
/usr/lib/pm-profiler/get-current-settings: line 137: : too many arguments

YUCKKKKKK!!! /me goes off to see if it’s like this in 12.1 M3