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    Y40 CPU Speed After Sleep

    Discussion in 'Lenovo' started by thurstone, Oct 23, 2014.

  1. thurstone

    thurstone Newbie

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    Has anyone here had an issue with their Y40 (i7 4510U) CPU running slower after waking from sleep?

    It's supposed to be a 2 Ghz CPU, but I rarely see that speed.

    I've checked my clock speed with a few tools, one simply being the task manager's performance tab.

    After Reboot: 2.91 Ghz
    After Sleep: 1.17 Ghz

    Performance in, e.g., games is significantly better when it says "2.91" I'm talking 20 FPS vs. 60 FPS in 3D games.


    Are there utilities to compare the freq / voltage I'm getting before / after sleep?


    Is there a way to "poke" the CPU the same way a reboot does, to get it back to full speed?


    It steps back up on its own sometimes as well.


    I'm assuming this is SpeedStep glitching out or something.
     
    thurstone, Oct 23, 2014
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  2. kevinwoodward

    kevinwoodward Newbie

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    I have this same issue with the same laptop. After a little but of searching, there is an available BIOS update. Under the summary of changes it lists "Fix the issue that after closing lid to enter sleep mode, CPU frequency will be locked after S3 or S4 resumes."

    I haven't installed the update yet, but it seems like a direct address to the issue.

    EDIT: the link

    http://support.lenovo.com/us/en/downloads/ds100938

    EDIT2: This has fixed the issue for me
     
    kevinwoodward, Oct 27, 2014
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  3. thurstone

    thurstone Newbie

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    Oh, awesome, good catch. I just updated as well and can confirm it fixed for me too.

    Now I don't have to reboot whenever I want to play a game.
     
    thurstone, Oct 27, 2014
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