The "Undervolting" Guide

Discussion in 'Hardware Components and Aftermarket Upgrades' started by flipfire, Apr 1, 2008.

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  1. brentbizzle

    brentbizzle Notebook Guru

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    From what I understand you need to change the processor state to 100% min in the windows power plan (at least on windows 7 you do).
     
  2. rdhood

    rdhood Notebook Enthusiast

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    From a configuration (rather than OS) standpoint:

    There is the Profiles page, and that is where you set up your voltages on each index. Check them all, set input voltage(s), click "Apply"

    One the Profiles page, you also set your Current and Startup management profile. Set "Performance on demand" for Current for both AC Power and Battery. Click "Apply"

    Now, go to the "Performance on demand" profile. make sure the "Use P state transitions" is checked for AC and Battery. Click "Apply". Then, click all of the indexes in each box. Click "Apply".


    On the OS (Windows XP), I went in to Control Panel, Power Options, and set "RMClock power management"

    At that point, I could watch the on demand voltage/frequency changes
     
  3. x60tp

    x60tp Notebook Enthusiast

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    Does anyone know if this program will work with an i3 processor? If not, what should I use? I don't want to mess up my machine.
     
  4. scott.ager

    scott.ager Notebook Evangelist

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    Apparently, it doesn't. Laptop components are now lighter and cooler and better designed so Intel doesn't need to incorporate powering down to protect their CPU's from overheating and cutting out anymore. It was fun while it lasted.

    I don't recommend power plan integration with W7. Let RMC do voltages and W7 do the speed switching and all the rest. For this to work, you must set the processor states (in percent) that you will be going to want to use ie. 100% to use the top FID.
     
  5. 1313

    1313 Notebook Enthusiast

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    Can anyone with a studio 15(35) or any other Dell laptop verify whether they can run their processor in superLFM mode? As in, it actually downclocks the FSB to half its normal value?

    I keep getting system hangs if I enable it, even with CPUgenie. I'm starting to think Dell has something to do with it, i.e. by not supporting it through the BIOS. Which would be rather idiotic since it means disabling a feature that can preserve more battery life which is not unimportant for a laptop, at least in my mind. As a matter of fact, CPUgenie doesn't list superLFM as a p-state found in the ACPI table in my BIOS.
     
  6. 1313

    1313 Notebook Enthusiast

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    How exactly would you do that? If I don't set my min. & max. proc. power states to 100% in seven, I get weird VID spikes even tough RMClock's profile is in control. I get this with OS power management integration enabled or disabled.
     
  7. scott.ager

    scott.ager Notebook Evangelist

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    The IDA spikes seem to go away during CPU processing and come back after prolonged idle. Maybe you can do an experinent for everybody and see if there is percentage somewhere below 100% that still gives top FID without IDA blips.

    On the surface, it might seem that SLFM would save battery. It doesn't. Because two FID's runing at the same voltage take the same watt-seconds of power computing a digital job before the going back to idle (no load). Twice the power for half the time is a wash. SLFM is a joke for battery purposes. Use Standby instead.
     
  8. red_ace24

    red_ace24 Newbie

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    Not sure if its been asked but I don't wanna go through 600 pages. How do I get the program to start without win7 asking me to click yes everytime I boot up?
     
  9. mb.email12

    mb.email12 Notebook Enthusiast

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    Wow great explanation!

    So I've now undervolted my Vostro 1500, but am worried because I dropped the voltage so much, even though no BSOD yet.

    Do the following numbers seem crazy low?

    6.0x 0.9500V
    7.0x 0.9625V
    8.0x 0.9625V
    9.0x 0.9750V.

    Also, I didn't mess with the SuperLFM and IDA voltages. Can I lower those to further drop heating?

    Thanks!
     
  10. Ferretwulf

    Ferretwulf Notebook Consultant

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    Quoting myself (used in both Vista and my new Win7 Laptops)

     
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