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    Undervolting C2D

    Discussion in 'Hardware Components and Aftermarket Upgrades' started by orca3000, Dec 11, 2006.

  1. orca3000

    orca3000 Notebook Evangelist

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    Is there any safe ways to undervolting Core 2 Duo? Apparently all the guides in the forum are for Pentium M.
     
    orca3000, Dec 11, 2006
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  2. Greg

    Greg Notebook Nobel Laureate

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    All the steps for Pentium M are valid for Core 2 Duo as well. The voltages are a a little different, as are the clock speeds. But the procedures are the same.

    Check out the Cooling Guide for undervolting with Notebook Hardware Control.
     
    Greg, Dec 11, 2006
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  3. orca3000

    orca3000 Notebook Evangelist

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    How much voltage can be safely taken out on average?
     
    orca3000, Dec 11, 2006
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  4. Greg

    Greg Notebook Nobel Laureate

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    Probably 0.200V but I'm not sure. It has been a while since I've worked with NHC.
     
    Greg, Dec 11, 2006
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  5. rockharder

    rockharder Notebook Evangelist

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    So far I didn't read any exciting undervolt result coming from Core 2 Duo or Core Duo, simply because Intel lock the minimum VID and makes many fans get nothing out of it. I don't know what you can do of its upper VID. Maybe you can do more of its max FID undervolt.

    Undervolt won't give you 20 mins more battery life unless you can do something at minimum FID. But it does reduce the heat especially those hot Mac potato(sorry Mac fans :) ). You probably read lot of P-M undervolt story under Linux. RMClock in XP makes you much easier for all latest CPU.

    Since Intel doing power management pretty well, I don't think you even need to do that.
     
    rockharder, Dec 11, 2006
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  6. John Ratsey

    John Ratsey Moderately inquisitive Super Moderator

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    I've just got a Samsung X60plus with the T7200. I used the Rightmark CPU clock utility and got the maximum voltage down to 0.975V before Prime 95 showed an error. I then did a longer test running two separate copies of Prime 95 (in order to fully load both cores) at a maximum voltage of 0.987V. Now I have set the voltage for 1.0V for normal use.

    The effect of dropping the maximum voltage is to give a useful drop in the heat generated when the CPU is fully loaded. MobileMeter shows a drop of 10W in total power used and about 7C drop in temperature (with the fan also running slower).

    As noticed by a previous poster, undervolting no longer gives any significant increase in battery operation tiume (unless the CPU is heavily loaded). Intel have locked the minimum voltage at an unnecessarily high level. I presume this is to encourage us to buy low voltage versions of the CPUs, although these are uncommon.

    John
     
    John Ratsey, Dec 16, 2006
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