Poor Lion battery life related to discrete gpu?

Discussion in 'MacBook Pro' started by XandeR803, Jul 25, 2011.

  1. XandeR803 macrumors member

    Jul 25, 2008
    I have the 2011 15" MBP with the 1GB 6750M. With all the threads flying around about the poor battery life, I've been taking a closer look at it the past few days and noticed that the automatic graphics switching in Lion seems to be a bit wonky. Using istat menus, I've been looking at the GPU voltage to determine if it is being activated or not. When it's activated it's usually 1.00V and when it's deactivated it's usually 0. Obviously, firing up an app like twitter or FCP activates the GPU and closing it should deactivate it.

    I've noticed several times now that after closing all my apps, the GPU voltage is still staying at 1 indicating that it's not deactivating properly. I even tried installing gfxcardstatus to force the intel gpu. The funny thing is, gfxcardstatus will report that the intel gpu is active, but istat will still show power being delivered to the 6750M. When the 6750M is being powered, my battery life is usually cut in half (3-4 hours) and when the intel gpu is active, my battery life is back to normal (7-8 hours).

    I've tried a clean install of Lion and been able to duplicate this right after installing the OS so I'm pretty sure it's not related to any settings or programs. Obviously this would only affect MBP's with discreet gpu's but I'm wondering if anyone else has noticed something similar.
  2. Lenas macrumors newbie

    Apr 28, 2011
  3. daveevans76 macrumors newbie

    Apr 9, 2011
    Flower Mound, TX
    I did see a post (https://discussions.apple.com/message/15683279#15683279) from someone on a Citrix agent taking up some of that life and you can kill it through terminal with:

    sudo launchctl unload -w /Library/LaunchDaemons/com.citrix.agadminservice.plist

    However, this did not work for me as I did not have this on my machine. Still perplexed on my shorter battery life. Think I might go back to Leopard until a later version of Lion is released.
  4. XandeR803 thread starter macrumors member

    Jul 25, 2008
    No. These were observations from a completely clean install of Lion with no programs installed (other than istat and gfxcardstatus).
  5. ABadSanta, Jul 25, 2011
    Last edited: Jul 25, 2011

    ABadSanta macrumors regular

    Jul 3, 2011
    Thanks for the tip. Just got gfxcardstatus and i put it on integrated only. ill observe it and see if it makes a difference.

    Edit and update: when on integrated only, I can't watch youtube videos at full screen with 720p or 1080p. Just letting everyone know.
  6. di1in macrumors regular


    Feb 27, 2011
    Likewise here: Lion always uses the discrete GPU which leads to the higher temps and lowered battery life. When i used gfxcardswitcher to change to integrated these problems go away. But then new troubles come up with youtube and other flash sites. They dont even load - just show a black screen.
  7. Silverbird0000 macrumors 6502a

    Sep 19, 2006
    Fort Myers, FL
    There is an easier way to tell what graphics card is in use. Go to the Apple logo on the top left of the screen, then about this Mac, then more info, then system report. Now go to the Graphics/Displays section. It will show both your graphics cards. Select each one, whichever has a display connected is the currently in use card. This only refreshes by closing and reopening, so if you start doing a graphics intense activity, reopen the about this mac window and look again. The display will now be connected to the discrete card.

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