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    W520 down-clocking with discrete card in battery

    Discussion in 'Lenovo' started by burk, May 18, 2011.

  1. burk

    burk Newbie

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    My CPU is 2820QM， but have some speedstep problem in battery mode.
    The CPU is always stay at 800MHz, even full loading with wprime.
    I Check BIOS and PowerManager, the setting of ac and dc is the same in performance mode.
    CPU's speedstep is normal when using ac, between 800MHz~3300MHz.

    After few testing for settings in BIOS and PowerManager, the only way to solve this problem is select integrated card in BIOS.
    When using integrated card in battery mode, CPU's speed wouldn't lock in 800MHz, would change between 800MHz~3300MHz.

    If discrete card or Nvidia Optimus selected in BIOS, CPU's speed is always lock in 800MHz.


    Anyone else have this issue?
     
    burk, May 18, 2011
    #1
  2. Colonel O'Neill

    Colonel O'Neill Notebook Deity

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    Maybe the battery can't handle the load of the discrete card and the CPU?
     
    Colonel O'Neill, May 18, 2011
    #2
  3. John Ratsey

    John Ratsey Moderately inquisitive Super Moderator

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    My initial thought is that this is by design to avoid a very high battery drain rate that would either be bad for the battery's health or the battery is incapable of delivering. See here for what happens to the Alienware M14x when gaming on battery.

    John
     
    John Ratsey, May 18, 2011
    #3
  4. stryfe

    stryfe Notebook Enthusiast

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    stryfe, May 18, 2011
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