Lower Performance when not on AC

Discussion in 'MacBook Pro' started by MaxZappa, May 26, 2008.

  1. MaxZappa macrumors newbie

    Jan 6, 2008
    Hello! I own a MacBook Pro 2,4GHz 2GB RAM with the 8600M GT 256MB somehow being recognized as a 512MB VRAM by games' analysis, playing Bioshock and Assassin's Creed with respectively maxed-out and close to maxed-out graphic settings, and I've only today noticed one thing: When I unplug the battery cable, leaving the MBP to the battery alone, the performance drops drastically. Not to mention that this baby gets HOT when playing. I couldn't be more proud of the performance when the lappy's on the electric current though.

    Question: Is it normal that I have to lower the graphics so much to play as smoothly when the battery's the only source of power? Or could it have been because it was too hot? I don't see why it should have such a slower performance, I thought it should eat up the battery in 1h instead of 4h, but not such a speed drop....

    Thanks in advance for the help!
  2. yellow Moderator emeritus


    Oct 21, 2003
    Portland, OR
    It's not lower graphics, it's lower processor speed.
    The processor scales back to conserve battery life.
    Yes, it's normal.
  3. MaxZappa thread starter macrumors newbie

    Jan 6, 2008
    OIC... Is it possible to change your energy settings running on Windows like you do in the Leopard?

    Thanks for the info ^^
  4. slu macrumors 68000


    Sep 15, 2004
    I don't have Leopard, but in Tiger if you go to System Preferences > Energy Saver.

    Change the "Settings for:" drop down box to Battery. Change the option for processor performance to Highest.

    This will decrease battery life.
  5. alphaod macrumors Core


    Feb 9, 2008
    Relative to plugged-in, on battery, the CPU mulitplier decreases, the video card frequency decrease, the PCI Express bus slows down, etc. Even if you turn on Maximum Peformance, it's unlikely it'll affect the GPU/Bus.
  6. Templex macrumors regular

    Jul 12, 2007
    Los Angeles, CA
    You might want to look at the PowerMizer settings in the NVIDIA Control Panel. There's also some other setting that lets you set how much the CPU clock speed is reduced, I think, but I only saw that in Vista, and I'm not sure where I saw it.
  7. aquajet macrumors 68020

    Feb 12, 2005
    It's long been known that there is no processor performance setting on Intel Macs. Only the PowerBooks and iBooks have this option.
  8. kgeier82 macrumors 65816

    Feb 18, 2008

    not true, "Coolbook"

  9. MaxZappa thread starter macrumors newbie

    Jan 6, 2008
    how do you delete posts? i'm sorry for this useless one here, it would be a repetition of the next one, in which I quoted, which I failed to do in this post in which you're reading this useless stuff, for which I'm sorry.
  10. MaxZappa thread starter macrumors newbie

    Jan 6, 2008
    Through the NVIDIA control panel, setting up the PowerMizer not to optimize battery life or save enegry, the problem remains. Can I set the CPU clock speed reduction through XP? I can't find it, maybe cause I don't even know where to begin looking at =P


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