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    A few questions about CPU frequency and voltage?

    Discussion in 'Hardware Components and Aftermarket Upgrades' started by moral hazard, Jul 24, 2009.

  1. moral hazard

    moral hazard Notebook Nobel Laureate

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    Hi,

    I have a T7300 CPU, 2ghz.

    If I underclock it with setfsb to 300mhz @ 0.85V will the CPU run cooler than 600mhz @ 0.85V?
    Will it give me better battery life?

    Now the other end of the spectrum, if I overclock it to 2.6ghz @ 1.2625V should it run any hotter than 2.0ghz @ 1.2625V?
    Will this give me worse battery life?

    I'v noticed when I do overclock it to 2.6ghz @ 1.2625V the CPU does get hotter than when it's at 2ghz. Why is this? It's not like I gave it any more voltage.

    So my question is;
    Does changing just the frequency (leaving the volatge stock) effect temperature or battery life?

    Last question, when I wan't maximum battery life should I underclock to 100mhz or does it make no difference when compared to 600mhz?
     
    moral hazard, Jul 24, 2009
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  2. 0.0

    0.0 Notebook Consultant

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    The voltage change will make more of a difference as it follows a square law, ie. if you increase just the voltage by 10% it will increase the power by 21%. The frequency is more of a linear change.

    IIRC there is a formula of something like Power=CFV<sup>2</sup>, where C=capacitance, F=frequency and V=voltage.
     
    0.0, Jul 24, 2009
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  3. moral hazard

    moral hazard Notebook Nobel Laureate

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    thanks for that, exactly what I was after.

    So I guess I will underclock to hopefully get some more battery time.
    The minimum setfsb lets me have is a 30mhz fsb, so 180mhz CPU.
    Is there going to be any problem if I run @ 180mhz?
     
    moral hazard, Jul 24, 2009
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