Linux Power Saving Tweaks for HP Pavilion laptops
Less watts: environmentally friendly, longer lasting battery, less spending on energy bills.
Thanks to these tips you’ll be able to improve your Ubuntu GNU/Linux laptop lasting, maximize battery lasting and life and also our own planet Earth life expectancy!
QUESTA GUIDA È ANCHE DISPONIBILE IN LINGUA ITALIANA
Just for reference on my HP Pavilion dv6500 series laptop I managed to get battery lasting to 3h average @ ~13Watts with kernel 2.6.24 applying the sysfs fixes only typing/reading with wireless on, screen 60%, desktop effects, laptop-mode enabled BUT NO hard disk spin down / powersaving features enabled.
A relevant gain which can be further increased (I managed to get as low as 8,5Watts by enabling hard disk power saving features in laptop-mode.conf. Notice it was not spin down but only powersaving!)
Check http://lesswatts.org for further tips on how to save energy, money and life expectancy!
Note: unless specified following tips will NOT DEGRADE your system performance since they work on demand and will activate only when your system has little load.
Note2: as Harry suggested, do not leave any empty line in sysfs.conf file.
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- With Laptop-Mode-Tools (great set of scripts coded by Bart Samwel) you get the chance to tweak the following power related features:
in /etc/laptop-mode/laptop-mode.conf
- Hard Disk related settings: readahead, cache, realtime, powersaving, spindown
- Cache related settings: dirty ratio, etc.
while in /etc/laptop-mode/conf.d/
- AC97 powersave
- Bluetooth powersave
- Logging files tweaking
- Syslog tweaking (through command lm-syslog-setup)
- CPU frequencies and governors (however Ubuntu has already Gnome that does this)
- Display dpms standby (however Ubuntu has already Gnome that does this)
- Display brightness (however Ubuntu has already Gnome that does this)
- Ethernet disabling (NOTE: autosensing even with AC doesn’t currently work for me)
- Hal polling
- Intel SATA link power management
- Scheduler power saving settings
- Video-out
- Wireless Intel IPW and IWL drivers powersaving features
- Start/Stop of programs and services on power source toggling (i.e. cron, crontab, cups…). These can be set through command lm-profiler
To enable laptop-mode-tools you have to edit both
/etc/laptop-mode/laptop-mode.conf
and (if you use the package from the repositories) also
/etc/default/acpi-supportYou may consider updating laptop-mode-tools from intrepid repositories. These have a new version which has more comprehensive power tweaking options:
http://packages.ubuntu.com/intrepid/laptop-mode-tools
NOTE: I advise against using the package provided from laptop-mode-tools maintainer website http://samwel.tk/laptop_mode/ since that wouldn’t resume its functionalities upon resume from suspend/hibernate. The package from the repositories, instead, provide a set of scripts for it to be always checking the power state (AC or Battery powered).
The aforementioned scripts are available here: /usr/lib/pm-utils/power.d/laptop-mode and relies on the new pm-utils framework.
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2. Enable Ethernet network CPU offloading (click here for the howto)
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if USB autosuspend is enabled at the kernel level there is no more need to tweak these settings, also because powertop reports them not being active and consuming power while not working.
# manage suspend of Authentec Fingerprint Scanner.
# Bus 004 Device 003 AuthenTec, Inc.
# timeout time (seconds)
bus/usb/devices/4-1/power/autosuspend = 2
# power level: on = always on; auto = autosuspend; suspend = always off
bus/usb/devices/4-1/power/level = auto
Note on USB devices addresses: to locate the USB device address in /sys you first have to ‘lsusb’ then keep in mind the ‘Bus 00N Device 00N’ relative to the device you want to manage. Go into /sys/bus/usb/devices and here look at the entries in this form X-Y (numberDASHnumber) and use ‘cat X-Y/busnum’ and ‘cat X-Y devnum’ in order to identify the correct device.
With this in mind you can apply this tweak to every USB device attached to your laptop (however it makes sense only for those embedded into the laptop (fingerprint, webcam, bluetooth), not the external ones).
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Enable low power state for Realtek HDA audio switch
(integer express idle seconds after which to power off the device)
note: audio led will toggle blue/amber according to active/powersaving state
Add the following line in /etc/sysfs.conf
module/snd_hda_intel/parameters/power_save = 10
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in /etc/X11/xorg.conf (your video configuration file) enable on demand V-Blank (which will reduce by 60 your kernel wakeups). This works for nvidia cards with nvidia 3D propietary driver.
under section “device” add following string:
Option “OnDemandVBlankInterrupts” “true”
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if you use GNOME you can add to the pannel a very useful applet, the LCD Brightness applet. This enables you to tweak the display brightness according to the environment light and your desired comfort/battery lasting.
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Gnome-power-manager has an interesting feature that allows you to dim screen brightness upon idle status. However you may only tweak the idle timeout from the registry with gconf-editor
run this application in ALT+F2 window and search for
/apps/gnome-power-manager/backlight/
tick enable
set brightness % when idle in idle_brightness
set the number of seconds after which to consider the computer idle in idle_dim_time
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Related posts:
- Tweaking GNOME power-saving settings
- laptop-mode and hard disk monitoring software
- HowTo: Ubuntu Linux on HP Pavilion series laptops
- nVidia PowerMizer powersaving/cooling in Linux (updated)
- Ottimizzazioni per il Risparmio Energetico per portatili HP Pavilion su Ubuntu Linux
- Pavilion two fingers touchpad scrolling
- SysRQ key combinations on HP Pavilion laptops
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I have found that my pavlion dv2775ee is very bad at power management. In vista is will run for about 2~2.5 hours. When I looked deep with powertop in linux, I found that although the cpu supports C1 C2 C3 C4 C5 C6, but the BIOS supports only C1 C2 C6.
Any idea?
Powertop does not show all the C states, nor all the P states. It does show only the relevant ones. The important thing is that it does show the lowest C state. If in your case you see C1, C2 and C6 I think there is no problem.
Have a deeper look at laptop-mode configuration tools, they indeed do help lower the power consumption along with powertop. Cheers!
Thanks, but I saw in some laptops that they support C4 and C5 and I think they are better. Also as far as I know, C0 is operating state and C4->C6 are designed to save power.
at C0 the whole CPU core is running, the higher the Cnumber the higher the powersaving (the lower percentage the CPU core is used).
Note that with CPU core I do not mean nor the Pstate (clock frequency) nor the CPU load. C states are related to power saving features only.
For instance a CPU with maximum state C6 is better than one that has max Cnumber 4.
Excatly… that is my question to HP… when C4 and C5 are good, why they did not implement it to their BIOS? In my case, the CPU will jump from C3 to C6 and vice versa. Since C6 may rarely used, the power management that come from the BIOS is useless.
now I got your point!
however there is not much to worry, you just have to make your CPU stay at C6 state as long as possible through reducing the wakeups. If you manage to keep the CPU at C6 state for more than 90% of time and more than 20ms you have achieved your goal. No matter the BIOS being buggy and hiding useful power states.
It should be an interesting work… Do you know how to keep COU in C6?
There is not an easy way… you should just see when your computer is idle which processes still do generate lots of wakeups and try disabling and removing each unneeded sercvie and program.
[...] 2008 04 01 – wireless LED now toggling on/off (at last!) 2008 04 02 – updated and improved my power saving tips, getting as low as ~13watts, no joke! 2008 03 31 – added support for Broadcom Wireless cards [...]
Hi,
I think HP Pavilions are very bad in power management (at least my DV2000). When the system is running on battery, the power icon does not show the remaining time. It shows only the percentage of the battery. Also in the performance monitor tool (in windows 7) that has a section for showing the power consumption in Watts (it also can show per process, power budget, I mean), I am not able to see the consumption.
The same is true for linux. In my ubuntu, I can not access the power consumption in power history icon. I have checked power meters for both windows 7 and linux on other notebooks (sony and toshiba) and they show the information. I also updated to the latest version of BIOS F.2E but nothing changed. I don’t know why stuffs at HP don’t correct this issue….!!!!