Monday, January 17, 2011

Battery Life Review

In a previous post I was asked what I was seeing when it came to power usage on the laptop. I thought it'd be interesting to do some tests and see what I could find.
Here's how I setup the computer:
  • Brightness = Max 100% (10)
  • On Demand CPU performance on = ( echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor)
  • Sound card power management enabled = (echo 1 > /sys/module/snd_hda_intel/parameters/power_save)
  • File System power saving = ON ( sudo echo 1500 > /proc/sys/vm/dirty_writeback_centisecs)

First Test
Wifi-Bluetooth-Web Browser (Chromium) = ON
ATI Discrete Graphics = ON
Intel Graphics = ONd
Power Usage = 54.1W
Second Test
Wifi-Bluetooth-Web Browser (Chromium) = ON
ATI Discrete Graphics = ON
Intel Graphics = OFF
Power Usage = 59.4W

Third Test
Wifi-Bluetooth-Web Browser (Chromium) = ON
ATI Discrete Graphics = OFF
Intel Graphics = ON
Power Usage = 17.7W


Fourth Test
Wifi-Web Browser (Chromium) = ON
BlueTooth = OFF
ATI Discrete Graphics = OFF
Intel Graphics = ON
Power Usage = 17.7W

Fifth Test
Wifi-Web Browser (Chromium) = OFF
BlueTooth = OFF
ATI Discrete Graphics = OFF
Intel Graphics = ON
Power Usage = 17.3W

Last Test
Wifi-Chromium = ON
BlueTooth = OFF
ATI Discrete = OFF
Intel Integrated = ON
Power Usage=20.5W

Now a suspend was done
Power Usage after Suspend = 44.2W



So to those that were asking. The suspend bug does seem to affect this system. Powertop isn't showing whats using the extra power either. Before and after suspend wakeups seem to be consistent.

6 comments:

  1. So, ATI does suck battery life.
    I would suggest using a solution like Win7 ATI switchable graphics.

    On bootup, if AC power, ATI on, Intel off;
    On bootup, if AC off, ATI off, Intel On;

    When running if power was later connected, ATI on, Intel off and a dialog to suggest to restart X.
    When running if power was later removed, ATI off, Intel on and a dialog to suggest to restart X.

    On shutdown, automatically enable both graphic cards.

    ReplyDelete
  2. Using the charging state as a switch to suggest graphics switching is a very good idea. Although right now I'm not sure it has much purpose. Without hardware acceleration I'm not sure there is much of a performance difference between the ATI and Intel chipset. I suppose that warrants a benchmark test to be verified. However right now since only the closed source drivers will enable hardware acceleration, and the closed source drivers break the graphics setup, then there isn't much point.

    Once we have hardware acceleration in the open source drivers or the closed source (Catalyst) drivers start working with the hybrid graphics then your idea would be an excellent one.

    Thanks for the comment and the idea.

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. I've been able to get down to 11 watts average (while running codeblocks and one terminal instance) with the following settings:

    System settings
    ---
    -Wifi = off
    -Bluetooth modules blacklisted
    -Integrated graphics, with discrete card powered down.
    -30% screen brightness
    -Sound muted
    -USB ports powered off
    -HD was completely wiped (including restore partitions and quickweb) before my install. Breakdown is 16 gigs to /swap, 15 gigs to / and remaining space to /home.

    OS Settings
    ---
    -Kernel: Ubuntu x86_64 SMP 2.6.38-10-generic
    -Link to my rc.local file: http://pastebin.com/ygUr0mcW
    -UI is classic mode (no effects)

    Installed power management packages
    ---
    -Jupiter
    -laptop-mode-tools

    I'm also experiencing the suspend bug. After a suspend my power use never falls below 20 watts. Hibernate doesn't appear to have the same problem, so I've just hibernated instead of suspending.

    ReplyDelete
  5. Check out this post to fix suspend bug. http://linuxenvy.blogspot.com/2011/09/ive-been-being-lazy.html?showComment=1315427419402#c4396376300869253470

    ReplyDelete