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Enabling CPU Frequency Scaling November 4, 2005

Posted by Carthik in administration, applications, guides, ubuntu.
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I use the CPU Frequency Scaling Monitor on my panel to see the speed of my CPU. I have a centrino laptop. Ubuntu automatically increases the speed (frequency) of my laptop when the demand is more, and manages things very well.

However, when I am plugged in, I want to run my laptop at the maximum possible frequency at certain times. It turns out that the CPU Frequency Scaling Monitor can also have the functionality to change the Frequency, by “Governing” the CPU frequency. However, by default, on my laptop, left-clicking on the Monitor in the Panel did not give me the option to change the frequency.

In order to be able to change the operating frequency, your processor should support changing it. You can find out if your processor has scaling support by seeing the contents of files in the /sys/devices/system/cpu/cpu0/cpufreq/

For example, on my system:

$cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
gives:

1300000 1200000 1000000 800000 600000

Which means that the above frequencies (in Hz) are supported by my CPU.
and…
$cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
gives:

userspace powersave ondemand conservative performance

All those are the different “modes” I can operate the CPU at. Userspace, for example, regulates the frequency according to demand. Performance runs the CPU at max-frequency, etc…

On the Ubuntu Forums, I read that one can manually change the frequency by executing commands like:
$ cpufreq-selector -f 1300000
which will set the frequency to 1.3 GHz.

Now, I was interested in being able to change the power mode (between the different values listed in the “governors” above, manually by using the Cpu Frequency Panel Monitor.

I found out from the Forums, again, that changing the permissions of the cpufreq-selector binary by doing a:
$sudo chmod +s /usr/bin/cpufreq-selector

will allow me to acheive this. However, I was curious as to why Ubuntu does not, by default, allow me to choose the frequency using the CPU Frequency Panel Monitor, and what the “right” or “correct” way of enabling this is.

With a little bit of detective work, I found the reason why things are the way they are in Bug #17604 :

Oh, please, not another setuid root application if we can avoid it. Which file does cpufreq-selector need access to to change the CPU speed? And why should a normal user be able to change the CPU speed in the first place? The automatic CPU speed works well enough for the majority of users, and control freaks can always use sudo to manually set the speed, or deliberately shoot themselves in the foot by making the binary suid root (as explained in README.Debian).

Anyways, since I really want to “shoot my self in the foot” using my CPU ;), so I read the readme:
$cat /usr/share/doc/gnome-applets-data/README.Debian

and as suggested in it, I did a
$ sudo dpkg-reconfigure gnome-applets
and answered “Yes” to the question regarding setting the suid of the cpufreq-selector executable. Now, by left-clicking on the CPU Frequency Monitor Applet, I can choose the frequency for my processor, and things couldn’t be better!!

P.S.: A lot of my detective work could have been avoided had I read the README in the first place. Stupid me.

Comments»

1. Alex Ravenel - November 6, 2005

I did this and got it working, but it seems like the CPU frequency will frequently revert back to computer control–it’ll stay where I set it for a bit, and then start auto-adjusting again. Have you experienced this?

Colin Brayton - December 27, 2009

I have, Alex. What is doing the auto-adjustment and how do I kill it with extreme prejudice? I discovered I did not need any of the scaling daemons (cpudyn, cpufreqd, powernowd) and thought uninstalling them all would leave me as boss man.

In the meantime, when I see the CPU starting to revert to lowest freq, I manually reset the governor with sudo cpufreq-selector -g (in my case) performance.

Confusing, even all these years and kernels later. I actually never had this problem in earlier versions of Ubuntu, just Karmic.

2. skippy - November 6, 2005

Thanks for this — I just installed Ubuntu on my Centrino laptop, and was curious why I couldn’t change the CPU speed. No matter what I did, my 1.7 GHz CPU was always being reported at 800Mhz by the panel applet!

Andrey - May 17, 2009

I’m guessing that current load on your CPU isn’t requiring cpu speed higher 800Mgz. Try to load CPU speed.

3. ubuntonista - November 7, 2005

Alex, If you check the preferences for the applet, you can enable “Governors” and “Frequencies” for control. Try setting the frequency using the frequency menu after you enable it. It will then sta y at one frequencies. Each of the “governors” modify the frequency at various times.

4. bautt - November 7, 2005

Thank You, your hint worked perfectly for me (IBM Thinkpad T42)

5. skippy - November 7, 2005

It doesn’t look like Ubuntu, by default, twiddles the governors or the frequencies when you switch between battery and AC. When I’m on AC, I want the performance governor at full speed. When I/m on battery, I want the userspace governor, so the frequency will scale according to usage.

I poked around /etc/acpi/, /etc/defaults/laptop_mode, and /usr/sbin/laptop_mode and finally came up with the following, that works:

Edit /etc/defaults/laptop_mode and add the following:

GOVERNOR_ON_BATTERY=”userspace”
GOVERNOR_ON_POWER=”performance”
FREQ_ON_POWER=`cat /sys/device/system/cpu/cpu0/cpufreq/scaling_available_frequencies \
| cut -f 1 -d ” “`

Save the file. Now edit /etc/acpi/power.sh. Below the like $LAPTOP_MODE strart (line 14 on my Breezy system), add the following:

/usr/bin/cpufreq-selector -g $GOVERNOR_ON_BATTERY

Then move down to find $LAPTOP_MODE stop (line 58 in the unmodified file) and add:

/usr/bin/cpufreq-selector -g $GOVERNOR_ON_POWER -f $FREQ_ON_POWER

Save the file. Yank your power cord. Note that the governor has switched to userspace:
cat /sys/device/system/cpu/CPU0/cpufreq/scaling_governor

Restore AC power, and run the command above, to make sure that the “performance” governor is in use. Make sure the CPU frequency is at its max.

Tested — works for me. Enjoy!

6. Alex Ravenel - November 9, 2005

Thanks, ubuntunista. That worked fine.

Now I can’t get Skippy’s idea working; I’ll have to tinker with that a bit more.

7. sbeam - November 16, 2005

tnx for the tip, just what i needed! :) your trouble shooting was definetly not a waste of time.

8. Daniele Medri » Blog Archive » Cambiare la frequenza del processore - December 2, 2005

[...] e rispondete “Yes” alla domanda relativa al suid di cpufreq-selector. Fatto questo, andate nelle preferenze della vostra applet.. et-voilà! Per ulteriori informazioni leggetevi i commenti di questo post. [...]

9. mrm - February 17, 2006

Very nice. Thanks for the tip.

10. MikeAngel - May 19, 2006

Hello there,
I am using Dapper with power manager 2.14.3 on Dell latitude 640. I inserted the lines in my conf but can’t see any changes. My sudo cat cpuinfo_cur_freq shows the max cpu speed regardless of the script. With the gnome cpu fre scaling monitor the changes seem to work, but not automated as I would hoped to. I suspect some other rights issue. What script is triggered when I unplug the AC cable?

Thanks
Cheers
Mike

11. Keith - June 1, 2006

I used both Ubuntu and SUSE Linux. In the latter, changing the governor is pretty easy and quick. I guess Ubuntu has set too much constraint on the security of the OS, such that it makes a big hassle to go through all the way just to enable a different frequency selection.

12. Roger - June 14, 2006

Hi . Im a total linux noob – how do U start CPU Frequency Scaling Monitor ? I seem to have downloaded the package in Ubuntu 6.06 – but I don t understand how to stat the application ? Can someone help me ?

13. Drake - June 19, 2006

Thanks, it seems I’m not the only one wondering why the applet doesn’t support frequency scaling in the first place.

Roger: in Gnome, right-click the menu panel on the top of the screen and select “Add to panel”. There you should find “CPU Frequency Scaling Monitor”

14. Erik Weibust - July 6, 2006

Is it safe to say that some cpus don’t support frequency scaling? Because, I don’t have a cpufreq directory in …/system/cpu.

Erik

15. utkwes - July 6, 2006

Yes, some CPUs don’t have frequency scaling

16. PodMonkeys - July 6, 2006

What if you seem to be missing cpufreq in the …/system/cpu/ path, but your system does in fact support scaling? (Does it in Windows) (Pentium-M 733 1.1ghz ULV)

Has anyone seen this behavior?

17. Gajes.nl » Make Documentation Easier to Read - July 10, 2006

[...] Debian (and ergo Ubuntu) has some of the best documentation in the world. The best thing about the documentation is that it is on your machine, not on the internet. However not many realize this, and many a problem that can be solved just by reading the documentation remains unsolved, and many a user resorts to forums, mailing lists etc when the answer is right there on their own computer. I am guilty too, having realized the power of RTFM-ing before. [...]

18. isma - July 25, 2006

I also got a problem kind of like PodMonkeys.
I have a Dell Inspiron XPS Gen 2 Intel Centrino 2.0 Ghz (supports 800, 1.06, 1.3, 1.6 and 2.0)

isma@SoulFire:/$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
2000000 1600000 1333000 1067000 800000

However I can’t seem to be able to use any of the frequencies other than 800 Mhz due to this:

isma@SoulFire:/$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
800000

How can i fix this ???

19. Richard Hughes - August 17, 2006

This should be integrated into gnome-power-manager soon.
See my blog for updates.

20. Catatan - Catatan Penting Sehari-hari » Blog Archive » Ubuntu itu mudah - August 18, 2006

[...] Handy applets for notebooks: wifi strength and CPU speed control I like to see the strength of my wifi connection, and also when any data is being transmitted, so I use the Network Monitor applet. Right-click a blank spot on the taskbar and select Add to Panel. Scroll down the window to the System & Hardware heading and click Network Monitor. Select it and click Add. A new icon should appear near the system tray. The four bars on the right indicate wifi signal strength. If you’ve got a compatible notebook, such as one containing an AMD chip or an Intel Mobile Pentium 4 chip, you might also be interested in the CPU Frequency Scaling Monitor, under the same heading in the Add to Panel dialog box. However, out of the box this isn’t configured to work properly. To make it work, open a shell and type sudo dpkg-reconfigure gnome-applets. Read and evaluate the warning about security and hit Enter and then agree to install cpufreq-selector with SUID root. Reboot the system. From then on, you can right-click the CPU-freq applet and select the speed you want the chip to run at. The Ubuntu Blog has an excellent write-up about this, which I advise you to read: http://ubuntu.wordpress.com/2005/11/04/enabling-cpu-frequency-scaling/. [...]

21. chosaq » 14 days of Ubuntu - August 21, 2006

[...] 2006-08-22: as suggested, I looked into cpufreq. Here’s a guide that explains what it is and how you can use it. Iusually set the “governor” to “conservative” and switch to a fixed frequency (e.g. 800 MHz) when playing a movie or watching a YouTube video. Works great so far — the temperature is still higher than on XP, but no extreme jumps anymore. [...]

22. Ronald Baljeu - August 23, 2006

In response to message 16 from PodMonkeys:
Try this: “modprobe speedstep-centrino”.

23. tales from the crypt( ) » Two weeks worth of Ubuntu - August 26, 2006

[...] CPU frequency scaling had, by default, its behaviour locked to automatic choosing of CPU frequency. All regarding setting unnecessary superuser powers to yet another application. Quoting: “And why should a normal user be able to change the CPU speed in the first place? The automatic CPU speed works well enough for the majority of users, and control freaks can always use sudo to manually set the speed, or deliberately shoot themselves in the foot by making the binary suid root”. And that’s the trick. Issue a sudo dpkg-reconfigure gnome-applets and answer “Yes” to the question regarding setting the suid of the cpufreq-selector executable. Now, when I left click the CPU Frequency Monitor Applet, I’m able to choose the behaviour (powersave, max. performance, etc) and/or the processor speed. Yay. [...]

24. Mike - September 16, 2006

Help. Ok I set up http://ubuntuforums.org/showthread.php?t=248867 and then added this utility to see it work. I’ve noticed only one processor changes and the other stays full out. Even if I put two icons up top and change them. One stays in Performance and the other changes.

25. Marcin Siedlarz :: Weblog » Archiwum bloga » Howto Enable CPU Frequency Scaling in Linux - September 29, 2006

[...] read more | digg story [...]

26. Munckfish.net » Blog Archive » Enabling CPU Frequency Scaling on Ubuntu - October 16, 2006

[...] Enabling CPU Frequency Scaling « Ubuntu Blog [...]

27. loboson - October 19, 2006

Is KDE better on this with the “Laptop configuration” system applet??

28. Todd - November 4, 2006

Perfect, this is exactly what I was looking for.

29. Linux and Other Stuff » Ubuntu Edgy and cpufreqd - November 10, 2006
30. Jan - November 14, 2006

Hi,
thank you guys for this howto. I followed everything here on my Asus F3JA and i do have the Scaling Monitor. I can set the according CPU speed but i still have the problem that my fan won’t spin down, no matter to what speed i set the CPU (Core 2 Duo 2200) and no matter if its under full load or idling. Could you give me a hint where to start debugging?
Thanks in advance!

31. lorenzo - November 23, 2006

Jan
I have the same laptop as you and still trying to find a way to solve the fan problem…
News?

32. paddy - December 4, 2006

Thank’s a lot, this is my very first blog comment and I only post it because without this post I would have searched for another 2 hours ;-)

33. jerome - December 9, 2006

Thanks for the wonderful guide. You let me save energy! I was ready to turn off the scaling feature completely.

34. Kaito - December 18, 2006

Great guide.

One thing:

The correct way is not to touch the /etc/default/laptop…..

It is the best if you create corresponding scripts in /etc/acpi/ac.d and
/etc/acpi/battery.d
Like:

/etc/acpi/ac.d/cpufreq.sh:
#!/bin/sh
/usr/bin/cpufreq-selector -g performance

/etc/acpi/battery.d/cpufreq.sh:
#!/bin/sh
/usr/bin/cpufreq-selector -g ondemand

Why isn’t it there by default? There is no suid problem because the whole acpi is running by root.

35. andrew - January 13, 2007

if userspace controls the speed according to demand, then what is ondemand for?

36. Ben - January 22, 2007

Thanks for that, it was a great help :)

37. Roel - January 26, 2007

Ondemand reacts a little faster at my acer travelmate 8003, userspace waits a bit to long before switching for my taste.

38. kumar - February 2, 2007

today I came over your blog searcing for the same problem and got it working. Thanks a lot . I now know where to come for my problem…

39. Jason - February 6, 2007

The ondemand mode changes speed based on usage, and is built in to the kernel. The userspace mode allows a user-mode program to tell the kernel where to set CPU speed at any given time.

40. Andrey - February 19, 2007

hello, i wanna install ubuntu in intel core duo 2. this fileserver in small office. have i any problem with it?

41. Adrian - February 22, 2007

Nice tutorial, thanks. Why is there only one cpu state, C1, in /proc/acpi/processor/CPU1/power ? I have the core 2 duo 2.13 ghz and a debian 2.6.18-4-amd64 kernel

42. Adrian - February 22, 2007

oh yes, by the way, scaling with the tools you mention functions perfectly .. the cpu frequency is reported to be 1.6 GHz when using the powersave governor.

43. amudi - February 28, 2007

thank you very much, it works great for me… :-)

44. Zach Sandberg - March 11, 2007

I have a Thinkpad Z60t, and inserted the two scripts into “ac.d” and “battery.d” This works great when the laptop is on and I plug and unplug the power, however when booting up the laptop on AC power it still resorts to “ondemand” which is annoying. I would think that linux would read those scripts during boot time, but evidently not. Is there a workaround for this, or am I the only one having this problem?

45. adrian - March 15, 2007

yepp, worked perfectly in Debian as well. This guide allowed me to use the ondemand governor (which I couldn’t do manually, with sudo cpufreq-set -g ondemand)

Strange behaviour for the console mode, yesterday i could do it today I cannot ..

46. Jimd3299 - March 18, 2007

Perfect solution! This allows the CPU Frequency Monitor applet perform similarly to the power management setting in Windows (setting to always on sets top speed performance for laptops)

Having to configure a cpu speed applet to “Run As..Root” (In Windows terms) seems a little silly.

While I appreciate the security concern of having suid on a utility file. For a desktop based installation of ubuntu and functionality that this specific to laptops (speedstep), I do not agree that the applet should have been written to only allow root-level users access to speed adjusting functionality.

Oh well, got me to run “sudo dpkg-reconfigure gnome-applets” and now my little PIII laptop is pegged at its top speed of 1ghz vs 700mhz. I’m happy

Wonder how many other users of older laptops, hoping to leverage the efficiencies of Linux over XP to get more performance are slugging along at the slower speed and not even aware of it??

47. Süleyman ÖZARSLAN’s Research Page » Blog Arşivi » HOWTO: CPU Frequency Scaling w/ Kernel Module - March 22, 2007
48. gaffa - March 22, 2007

I gave up on frequency scaling. The power consumption is not notably lower.

My CPU (Spec#: SL4SH) is not fully supported by the p4-clockmod module. It reports wrong frequencies, but it works fine as the scaling is done as percent of the clock rate. It is just the reported clock rate which is wrong.

If you are using a P4 CPU you may need to manually modprobe the p4-clockmod module. At least I had to (6.10).

sudo modprobe p4-clockmod
sudo /etc/init.d/powernowd start

If you want to you can use the labtop_mode io scheduler to save some power/wear on your HDD. It takes a lot of power/wear to do spin ups on your HDD so it will only work if you find the balance that makes it worth it and doesn’t increase wear/power consumption.

sudo /usr/sbin/laptop_mode start
sudo hdparm -S 4 /dev/hda

The -S parameter is the spindown timeout in seconds divided by 5.

49. eris ascendant » Blog Archive » Adventures in Ubuntu - March 31, 2007

[...] though, I found out that I can still manually dim my laptop’s screen through the keyboard and this page showed me that I can manually switch my CPU to operate at lower speeds to conserve power. In [...]

50. Jason - March 31, 2007

I did what this guide says, now I have the selector for my scaling.
But if I click on any of the frequency, the speed on my laptop doesn’t change.
On another note, my laptop’s available governor only has one, the “performance” one. Doesn’t have a big list of them like yours, could that be why I can’t change it?
Lastly, I find if I start my laptop up without it being plugged in, the max speed will be at 1.4ghz, while if I start up my laptop with it plugged in, I get 1.5ghz. Any way to change this?

51. Jose - April 2, 2007

Very useful, Thanks a lot!!

52. nyinge - April 23, 2007

The method works great with minimal configuration. Awesome work! Thank you.

53. hobbesBlog » Blog Archive » The Linux Kernel for my client - May 6, 2007

[...] ACPI Support –> <> AC Adapter <> Battery (Note: For the next settings, I used this link and this Gentoo Wiki entry) CPU Frequency scaling –> <> ‘ondemand’ cpufreq policy [...]

54. unstable - May 12, 2007

Very informational
Searched via google, found this page, read it, fixed it. done.
Thumbs up.

55. Docunext Tech Stuff » Blog Archive » Linux Power Management - May 15, 2007
56. Damian - May 21, 2007

I did the whole set suid bit (Ubuntu Feisty – $ sudo dpkg-reconfigure gnome-applets and answered “Yes” to the question regarding setting the suid of the cpufreq-selector executable) and it works fine *most of the time*.

From time to time, however, I click on the applet and it *won’t* change. Usually when I’m trying to get updates or using Synaptic or some other process where I’ve used sudo/entered my password to give a process root privileges.

Does anyone know if this is connected?

57. manuel - May 25, 2007

@ What you describe is the moment when your machine wants to power up Synaptic. Do you have the same problem with the governor “powersave”?

58. manuel - May 25, 2007

On my T60 (Core2Duo T7200) changing frequencies has no effect on battery wear.
The Frequency Scaling Applet shows the change in frequency. Well, at least when I change the frequency by hand.
But the remaining time on battery power remains unchanged and conky also shows full frequency all the time. And the fan is always running. Any clues anyone?

59. matthew - June 18, 2007

Thinkpad T60 Core2 Duo

Thankyou for this. : )

“sudo dpkg-reconfigure gnome-applets” seemed to work well.

60. mgratzer’s Blog » Scaling the CPU Frequency in Ubuntu - July 10, 2007

[...] Scaling the CPU Frequency in Ubuntu July 10th, 2007 I really like my laptop, Sony did a great job constructing this series with small size and good performance. The downside of of good performance on small size is noise! When running on full load with 1.7 GHz my VGN-S5 makes too much noise for my sensitive ears. The fan is working all the time and drives me mad! On Windows XP the CPU scaling works fine, Vista needs more performance and the noise level is higher than in XP (or the scaling is badly implemented). But within Ubuntu the CPU is running with 1.7 GHz all the time and no scale down happens by default. This seems to be a bug and today I wanted to solve this problem, with success. I found a nice description at the Ubuntu blog on WordPress.com. [...]

61. The Linux Kernel for my client at hobbes.ch — thomaskeller.ch - July 13, 2007

[...] ACPI Support –> <> AC Adapter <> Battery (Note: For the next settings, I used this link and this Gentoo Wiki entry) CPU Frequency scaling –> <> ‘ondemand’ cpufreq [...]

62. jeanphe - July 18, 2007

works!!!

toshiba a100 va9 (centrino dual core 1.67ghz)

thank you so much

63. Victor - July 30, 2007

Thank you so much. Thank god for google and kind hearted bloggers such as yourself for the help you give to the rest of us. Your very simple method works great on a brand new core2duo T7500 in a Thinkpad X61.

64. Undervolting + Amilo 1425 = Leise unter Ubuntu ! - CoreBlog - August 8, 2007
65. Gary Klopfeger - August 9, 2007

I have a Toshiba a100 also with us centrino dual core 1.67 GHz processor. It worked very well thank you very much

66. Johann - September 18, 2007

DUDE! I love you :-) That was a GREAT and to the point tutorial on this. Thanks for taking the time to post the info you found – much appreciated!!

peace,

Johann

67. zombiez.uni.cc - September 21, 2007

Thanks work great for me

68. pharmamaster - October 5, 2007

I also got a problem kind of like PodMonkeys.
I have a Dell Inspiron XPS Gen 2 Intel Centrino 2.0 Ghz (supports 800, 1.06, 1.3, 1.6 and 2.0)
http://soundproducer.blogspot.com/

69. Web Hosting - hi i have static ip dapper 606 but i want to upgrade to 704 is there any easy way to do this from within ubuntu or do i - October 13, 2007

[...] you might want to take a look at this page: http://ubuntu.wordpress.com/2005/11/04/enabling-cpu-frequency-scaling/ [...]

70. someone - October 21, 2007

still works on ubuntu 7.10:

sudo chmod +s /usr/bin/cpufreq-selector

71. someone else - October 21, 2007

Works well for me too (Thinkpad R50e with Gutsy). Thanks :)

72. SEO Test - October 23, 2007

thanks!

73. munka - October 23, 2007

Wish I had found this about 40hrs ago, no matter fixed now, thank you :)

74. Moschops - October 27, 2007

Thanks – took me a day of searching for this. I had it working before in Feisty have done it before myself but forgotten how, maybe this time I will remember…

Frustratingly I found screen shots of the applet preferences with a “Show menu” option that would let it display the governor change menu, but mine didn’t even have that.

It is possible to make a manual change to the on AC and on BATT values from the Gnome configuration editor – under /apps/gnome-powermanager/cpufreq/{policy_ac, policy_battery} – but I like to change it depending on what I’m doing and how long I think I’ll be on battery…

75. Rene Dohan - October 29, 2007

works , thanks

76. How to make the menu show up - November 9, 2007

To make the menu show up when you left-click on the CPU Frequency Scaling Monitor, simply run the following in a console:

sudo chmod +s /usr/bin/cpufreq-selector

That’s all you have to do. That will “setuid root” for that application, letting a regular user run it and thus letting the handy panel icon change your CPU scaling settings.

77. Bunjatec - December 29, 2007

thanks! you just increased my battery life by 25% and cooled my lappy enough to stop it crashing :)

78. Alex - January 1, 2008

Hi guys
I have recently changed my laptop to ubuntu 7 but I have a problem with connecting to Internet. It’s working properly when I use DHCP but when I connect to router and set IP, DNS, … it doesn’t work. Can you help me with this thanks.

79. Trey - January 26, 2008

Alex,

I used to have that problem… I googled and looked all over the internet for an answer and did not find one. I finally installed Tomato on my Linksys router. Tomato supports static DHCP. Now I just assign static DHCP addreses.

80. Carlos - March 6, 2008

With ubuntu 7.10, there’s an easier way, if you don’t mind tweaking with gconf-editor. Drop a console, type gconf-editor, then choose apps > gnome-power-manager. You’re looking for the cpufreq folder, and the parameters you want to change are policy_ac set to performance and policy_battery set to either ondemand or powersave.

81. links for 2008-03-25 » oneafrikan.com - March 25, 2008

[...] Enabling CPU Frequency Scaling « Ubuntu Blog (tags: battery thinkpad t42p ubuntu linux cpu frequency laptop howto tuning) [...]

82. JAMS - July 10, 2008

Thanks a lot, now my laptop is running at full speed when power connected

83. Wyrenth - July 16, 2008

This is not working for me. I am trying to force maximum speed, and it first it seems to work, but then it scales back down to 800 MHz. I did the reconfig, I did the chmod, neither one seems to permanently fix it. Help?

84. kushelmex - August 9, 2008

dude thanks a lot i was looking for that!

85. mac daddy - August 17, 2008

Wtf is this article saying? Is this some sort of high level alien language?? Why can’t I just click a button here and there and enable scaling?

86. Linux daddy - August 18, 2008

@mac daddy
Don’t ask questions you wouldn’t understand the answers ;-)

87. FedosIS - September 23, 2008

thnx, i’m so stupid to) showld read README first… not search the net… this is not LINUX way. )

88. overuseee.com » Blog Archive » EeePC CPU throttling - ubuntueee - September 29, 2008

[...] some googleing I found an old (2005) post, which helped [...]

89. Kiran Jonnalagadda - October 7, 2008

Thanks a bunch, Carthik

I just installed Intrepid Ibex beta and found it was using the userspace governor by default, when plugged in, reducing the CPU speed down to 800 MHz. I’ve enabled the applet and suid bit and switched to the performance regulator, although it would sure be nice to have it integrated into the Gnome Power Manager as someone has mentioned above.

90. meganox - October 16, 2008

You don’t need to edit any config files anymore, this has been integrated into the power management UI in Hardy but is not enabled by default.

To enable it, run gconf-editor and navigate to the key apps -> gnome-power-manager -> UI -> cpufreq_show and check the box.

Now if you access power management through the preferences menu or the applet right-click menu you have the following options for Computer speed policy on AC and battery power: Always maximum speed, Based on processor load and Maximum power saving.

91. Jordan - October 30, 2008

In Intrepid Ibex (8.10), the applet will ask for permission (the root password) before allowing you to modify the CPU speed. This makes more sense than allowing all users to change the policy, and is more convenient than requiring a special command to set the policy.

I have noticed substantially increased battery lifetime when using the more conservative settings, so it *is* actually worthwhile.

92. Electronic Manufacturing - November 27, 2008

Perfect, this is exactly what I was looking for.

93. luke - December 16, 2008

the person who said

“Oh, please, not another setuid root application if we can avoid it. Which file does cpufreq-selector need access to to change the CPU speed? And why should a normal user be able to change the CPU speed in the first place? The automatic CPU speed works well enough for the majority of users, and control freaks can always use sudo to manually set the speed, or deliberately shoot themselves in the foot by making the binary suid root (as explained in README.Debian).”

is an utter cretin.

94. brian_p - January 4, 2009

Yeah, well said, Luke. Your masterful analysis is vastly superior to anything this Martin Pitt can quote.

95. Allen - February 22, 2009

I have my CPU scaling working fine, with the applet:
CPU Frequency Scaling Monitor 2.24.1

My question: How do I add my own, personally defined governor? I want something between “Ondemand” and “Performance” These setting must be listed somewhere, for example the governors are listed in “scaling_available_governors” how can I define my own governor without installing another applet (and perhaps cause conflicts with my other applets)

96. Allen - March 10, 2009

If anyone had helped, I would say “thanks”

I installed powernowd and in
/etc/default/powernowd I modified the options:
OPTIONS=”-q -u 30 -l 5″
this gives me a much more responsive “on-demand” governor.

97. ilvio - March 17, 2009

Hi all! It is possible save a default setting startup for CPU Frequency Scaling Monitor? every time i restart change are lost, what i can do?

98. Anthropos - March 31, 2009

How do you set an governor as default? Thanks in advance.

break19 - September 6, 2009

See my Message further down, regarding setting defaults

99. David - June 18, 2009

Thank you very much. This was able to get cpu frequency scaling working on my emachines t3522. Ubuntu previously had said cpu frequency scaling wasn’t possible.

However I too would like to know if it is possible to have this done automatically at boot.

100. Laptop running hot using ubuntu 9.04 - Page 2 - TechEnclave - July 7, 2009

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101. break19 - September 6, 2009

Anthropos : create the file /etc/default/cpufrequtils

Inside it, place the following, obviously, change the governor and/or speeds you wish to use. When you reboot, cpufreq will read this file to determine your chosen settings. FYI: Setting speeds to 0 will set max and min to whatever your CPU supports, respectively.

ENABLED=”true”
GOVERNOR=”performance”
MAX_SPEED=”0″
MIN_SPEED=”0″

My Settings, since I have a POS Asus board that frequently thermal throttles my 6000+ 90W cpu at 42C core temp

ENABLED=”true”
GOVERNOR=”ondemand”
MAX_SPEED=”2.8Ghz”
MIN_SPEED=”2Ghz”

Now, these settings mean my two cores will always be running at -LEAST- 2ghz each, and, under load, will ramp to 2.8Ghz each.. this helps my CPU from hitting 42C

102. mika - September 24, 2009

Hi

Thanks a million “break19″.
I’ve been looking an answer to get cpu frequency governor settings staying through boot ups and your advice seems to work.
Great.

Mika

103. paulo sampaio - September 24, 2009

I’ll reply just ’cause it helped me, and I believe that will keep helping others.

In debian 5.03, i installed it from the network cd, great, configured the wifi, the sound, and nothing more. So the cpu applet would just show me the cpu freq, wich is useless… So, now, it works!

Hope other debian users will be happy with this.

Thanks!

104. Kerne - November 6, 2009

Thanks my friend!
That halped me a lot!!!! I am using Ubuntu 7.10 here yet and at least here it kept changing CPU frequency to 800MHz all the time making my AMD TL-58 Dual 1.9GHz to run slower (really too slow) than normal.

105. AKay - November 19, 2009

Still struggling

106. topdstyoppo - November 22, 2009
107. key ödemeleri - December 8, 2009

key odemesi

108. alquiler de yates de lujo - January 21, 2010

every time i restart change are lost, what i can do?

109. Yacht rental - January 21, 2010

FYI: Setting speeds to 0 will set max and min to whatever your CPU supports, respectively.

110. opexpert - January 27, 2010

OpExpert is a unified solution to manage the entire IT operations for any organization, small or big. The functionality includes Enterprise Management, Performance Management, Fault Management, Network Performance Management, Server Performance Management, Virtualization Management. http://www.opexpert.com

111. karatedog - March 4, 2010

CPU Frequency Scaling Monitor simply sucks. Version 2.28 is not able to do the most simple thing on Earth: changing all CPU speed by one click (I mean, a single “all CPU” entry should be put in the drop-down menu).
Now that every CPU has at least 2 cores, I wonder how people didn’t find it frustrating to have 2 of the same applet on their desktop, not to mention quad core CPUs.

112. Mide Kelepçesi - March 19, 2010

with aesthetics on this site … thank you very much for all managers

113. algdfa - April 28, 2010

Subject Mfbd can not forget the experience, thank you

114. bayan escort - May 2, 2010

thankss admin

115. Alquiler de barcos en Ibiza - May 4, 2010

If you check the preferences for the applet, you can enable “Governors” and “Frequencies” for control. Try setting the frequency using the frequency menu after you enable it. It will then sta y at one frequencies.

116. Alquiler de barcos en Ibiza - June 4, 2010

PU frequency scaling had, by default, its behaviour locked to automatic choosing of CPU frequency. All regarding setting unnecessary superuser powers to yet another application. Quoting: “And why should a normal user be able to change the CPU speed in the first place? The automatic CPU speed works well enough for the majority of users, and control freaks can always use sudo to manually set the speed, or deliberately shoot themselves in the foot by making the binary suid root”. And that’s the trick. Issue a sudo dpkg-reconfigure gnome-applets and answer “Yes” to the question regarding setting the suid of the cpufreq-selector executable. Now, when I left click the CPU Frequency Monitor Applet, I’m able to choose the behaviour (powersave, max. performance, etc) and/or the processor speed.

117. escort bayan - July 6, 2010

Hmm…I’m not sure if this works for me. It would appreat the script is executed when I shut down, not when I log in.

Also another question: the script I want to roon requires root access. Do I need to do anything sepcial?

118. panjur tamiri - August 10, 2010

panjurcu

119. Tim Allingham - August 18, 2010

I realise this is quite an old post, but its still ranking highly on google results and getting comments, so….

Do you think you could update the content to reflect the correct way to achieve this?

To do this correctly the following steps are involved

1) Create a new group, say cpuadmin
2) edit /etc/cpufreqd.conf and find the lines like
#enable_remote=1
#remote_group=root

uncomment these lines, and replace
remote_group=root
with the group you created, ie
remote_group=cpuadmin
3) add any users you want to have control over cpu scaling to the group cpuadmin
usermod -a -G cpuadmin
once user has logged out and back in, settings will apply to them

120. porno sikiş - September 27, 2010

Thank You, your hint worked perfectly for me

121. sex sikiş - September 28, 2010

Very nice. Thanks for the tip.

122. ngiwutz - October 9, 2010

very nice thank you

123. Meins321 - October 20, 2010

Hello!
I am running the infamous 10.04 UNR with locked gnome panels…

is it somehow possible to add the “CPU Frequency Scaling Monitor” by editing the xml files that control the gnomepanel?

Thank you!

124. porno - October 28, 2010

Thank You, your hint worked perfectly for me

125. porno - November 1, 2010

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126. Disabling CPU Frequency Scaling in Ubuntu Linux 10.04 « Mostly Ramblings - November 14, 2010

[...] One thread suggests the following: create the file /etc/default/cpufrequtils [...]

127. escort bayan istanbul - January 16, 2011

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128. Play Ms Pacman - May 25, 2011

This sounds very unnatural

129. ukrayna vizesi - July 30, 2011

İYİ

130. antalya böcek ilaçlama - August 7, 2011

Thanks my friend!
That halped me a lot!!!! I am using Ubuntu 7.10 here yet and at least here it kept changing CPU frequency to 800MHz all the time making my AMD TL-58 Dual 1.9GHz to run slower (really too slow) than normal.

131. rulman - August 17, 2011

iyi

132. bob - August 25, 2011

I have installed ubuntu 11.04 on my sony i7 cpu, I have put the frequency on the lowest level, but my laptop getting a little bit overheat compared with when I am in win7 environment. How can I fix this problem?

133. NAKLİYAT - October 8, 2011

THANK YOU. SEE YOU

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135. lolo - March 20, 2012

hi ,
i used cpufreq in my work i want now disable it for work reason ,can any one help me ,i used ubuntu 10.04
thanks alot

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