Undervolting My D610

Discussion in 'Dell' started by Nicholas Andrade, May 24, 2006.

  1. I read a while back that the Penitum-M can run quite stable at lower
    voltages that what Intel specifies for default, so I finally decided to
    give it a shot. The Gentoo wiki had a great how-to [1] and it so
    happens I was already running a patched kernel (beyond2) so I decided to
    give it a go. On my P-M 760 (2.0GHz) I use:

    $ cat /sys/devices/system/cpu/cpu0/cpufreq/op_points_table

    The number before the colon is the frequency in Hz, and the number after
    is voltage in mV. My initial frequency:voltage was:

    So far my system has been stable and noticeably cooler. As you can see,
    the difference in voltage is 200+ mV across all steps, this is roughly a
    10% decrease in total power consumption (it's closer to 15% in low power
    modes with the screen dim). When I get a chance I'll be curious to see
    how much this helps the battery life.

    [1] http://gentoo-wiki.com/HOWTO_Undervolt_a_Pentium_M_CPU
    Nicholas Andrade, May 24, 2006
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  2. I should have said total voltage consumption, now power, they're related
    but definitely not the same.
    Nicholas Andrade, May 24, 2006
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  3. Nicholas Andrade

    journey Guest

    Hmm, I've heard a lot about overclocking, but this is the first I've
    heard about undervolting. I am certainly one to favor the latter on
    my notebook systems.

    I am going out on a limb here and am about to be pounced on probably
    by the emotionally-invested-Latitude-D'ers, but I have heard of and
    experienced overheating (/ undercooling) with the Latitude D series.
    When I sold my D505 the person who received it said there were
    noticeable signs of overheating and he wasn't happy.

    (which of course prompted me to send him more stuff to make him happy,
    and he did turn out to be happy and said "he's one of the BEST
    e-bayers"). I'd be happy too if I received an extra battery, extra
    power supply, extra CD ROM drive, and carrying case!

    I do remember it running very hot, and I have heard this about the
    Latitude D600 series too.

    Anyway, I find this very interesting and I am impressed by what can be
    accomplished by tweaking some "commands" or "settings".

    A friend who's a real geek (as opposed to me, an imposter) has
    recommended Gentoo. We tried to install it a while back on one of my
    laptops but it balked at it having one partition or some nonsence like
    that. I don't know, I'm willing to give it another shot but I would
    like to install Linux on an external USB hard drive, and be darn sure
    that I understand what happens in detail during the boot process so I
    can recovery if something goes wrong... Also, I don't just want to do
    an install, if I am going to do it I might as well jump right in and
    what -- compile the Kernal or whatever else is good to learn the right

    (I just realized that sometimes when I hear "Linux" the Peanuts
    character comes to mind! Just wait until Snoopy comes out, that will
    be one kick a** OS).

    journey, May 24, 2006
  4. I'd love to try this on my WinDoze D610, but I'm not ready to convert
    to Linux yet. Any idea if this is possible under XP?
    William P.N. Smith, May 24, 2006
  5. Yeah. that's actually where I first heard about it. This [1] is the
    original thread I read about it, and this [2] is another article on it.

    [1] http://www.notebookforums.com/showpost.php?p=762194&postcount=1
    [2] http://www.nordichardware.com/Articles/?skrivelse=465

    In Linux it's fairly straightforward to set it to undervolt at boot, but
    there isn't much point if I'm plugged in so I think I'll write a little
    ACPI script that undervolts the processor when it goes on battery and
    resumes normal operation when back on AC.
    Nicholas Andrade, May 24, 2006
  6. Recompiling your kernel is one thing, but I would never recommend Gentoo
    (even a stage 3 install) for someone starting with Linux. The distros I
    mentioned in my previous post on the subject (in the Remote Desktop
    thread) are all good for people beginning Linux. You'd probably like
    Fedora Core 5 a lot as it has tons of cool features and although it's
    good for people beinning Linux, it's not dumbed down at all.

    Gentoo is just very non-standard (eg. it's init scripts are different
    from any other distro, it uses USE flags when compiling, etc.) and is
    much closer to Linux from Scratch than any other distro. It is much
    more command line oriented and if you don't know what you're doing
    you'll likely be so frustated that you'll turn your back on Linux. The
    first time I installed Gentoo I had messed up my master boot record and
    it took quite a bit of web searching to figure out how to repair it to
    the point that I could boot to any OS.
    Nicholas Andrade, May 24, 2006
  7. Nicholas Andrade

    journey Guest

    Could running at a lower voltage cause problems with other components
    expecting a higher voltage? I don't know how much of a balance there
    is involved with it but I'd hate for it to screw up hard drive timing
    or have some other unforeseen problem.
    journey, May 24, 2006
  8. Nicholas Andrade

    journey Guest

    Thank you for the sound advice. The key words are: "if you don't know
    what you're doing you'll likely be so frustated that you'll turn your
    back on Linux".

    I had to develop Java apps on a "Unix" machine once. Probably
    non-standard, it was my short-lived foray into a Mac Powerbook. It
    took me forever to set up "Ant" one of the Java open source tools we
    needed to use, and I hated the Mac so much.

    So, starting out slowly and working up makes sense. I have played
    with Fedora Core before. I ran into problems with Broadcom wireless
    cards. Maybe because I purposely went with Intel I will be better

    Actually I think I'll start out on my desktop system so that won't be
    a factor right away.

    I remember my instructor, a Mac user, talk about how much faster the
    G4 chip is compared to anything Intel produced, and later when Apple
    moved to Intel it touted the speed improvements.

    My teacher also swore that an Intel Mac would never run Windows either
    (definitely a case in point supporting independent thinking not
    blindly accepting what a respected teacher says). He also thinks
    there will be an iPod phone -- hah, maybe but it's more likely that
    the iPod is going to see a fall and the Power PC / Palms will get the
    storage capacities of the iPod (why not, the form factor would seem to
    support it). I think Apple should have bought the Palm OS and made a
    Palm / Phone / iPod. Now that would be a killer device and another
    feather in Steve Jobs' hat.

    As it stands now, with other sources of music opening up, and MP3
    players becoming commoditized, iTunes and iPod and the proprietary
    standards of Apple and Audible (a stock I made tons of money on), they
    are set for a fall, and Apple's dual-boot strategy is likely to
    backfire. I doubt you'll see many PC people moving in the direction
    of the Mac OS especially with the likely appeal of Vista on the
    horizon, but Mac users are probably going to like the additional
    software choices of a Windows PC (as well as being able to use pirated
    versions or versions from friends -- game players will have more open
    to them too) and if the future Apple hardware won't support a Mac /
    Vista dual boot I think you will see defectors.

    I don't know how to short a stock but if I did I would be looking for
    an opportunity to do that with Apple stock.


    journey, May 24, 2006
  9. Nicholas Andrade

    journey Guest

    Oops, mistake number two tonight ... replace "Power PC" with "Pocket
    PC" above. The terms sound the same but they couldn't be more

    Journey :)
    journey, May 24, 2006
  10. Nicholas Andrade

    journey Guest

    There's a setting I think in my 630m P-M bios I think for turning the
    speed down so it's set at the lowest level. I've been tempted to see
    what setting it at that would do to battery life. Maybe I'll try that
    and post the results...

    journey, May 24, 2006
  11. Nicholas Andrade

    journey Guest

    The setting of "Speedstep Enable" when set to off, according to the
    Bios description, "places the system into the lowest performance state
    and prevents the Intel SpeedStep applet or native operationg system
    driver from adjusting the processor's performance".

    So one might think that turning it off would result in longer battery

    Results -- not scientific, but I did not notice any real improvement
    of battery life, probably because the average usual state of a
    speedstep laptop is at low clock speed anyway. When booting up the
    CPU seemed to stay around 80-100% for much longer time, and the laptop
    felt warmer than usual. If anything it seemed like the battery life
    was a little less than with the Speedstep turned on.

    journey, May 24, 2006
  12. Forcing the lowest CPU frequency and undervolting are neither the same
    nor mutually exclusive. With undervolting, you're saving over 200mV
    across all CPU frequencies. Yesterday I forced my CPU to use the lowest
    frequency (which can be done in userspace in Linux, no need to touch the
    BIOS) and dimmed my screen all the way; I then checked how much curreny
    I was drawing and it was about 1100mA. My battery is 4700mAh (with my
    last full charge being a little over 4000mAh) so that would be almost 4
    hours worth of charge.
    Nicholas Andrade, May 24, 2006
  13. Starting with Gentoo would be a mistake in my opinion (although it's a
    great distro, I'm using it now). It would almost certainly leave a bad
    taste in your mouth for Linux, which would be a shame. In my opinion
    you do learn a bit from the install (esp. a stage 1 install where you
    pretty much compile it from bootstrap), but if you don't understand the
    necessary tools (fdisk, gcc, etc.) then you'll get yourself in trouble.
    Recompiling your kernel is fairly straight forward, can be done in any
    distro, and typically results in improvements to performance.
    Well Ant is still a hassle, but it is getting better. The last couple
    Fedora Cores have included the Eclipse IDE which is quite nice for Java
    The Broadcom card definitely works in Fedora Core (and most distros)
    however it requires what is known as the ndiswrapper. Basically
    Broadcom refuses to offer any documentation on their wireless card to
    kernel developers (claims government defense contracts forbid it), so
    the developers came up with an ingenious solution. They take the
    Windows driver and put a wrapper around it to interface it with the
    linux kernel. I believe including the ndiswrapper module with the
    kernel might be a violation of the GPL (under which the kernel is
    licensed), so you have to download it separately (as well as download
    the Broadcom Windows driver). If you had the Livna repository listed in
    your yum.conf, then the command: yum install kernel-module-ndiswrapper
    would have taken care of installing the wrapper.

    The Intel card is a much better choice in Linux, because Intel has open
    sourced their drivers. You can do tons of great things with it (in
    particular set it to monitor mode -- which is very useful to my
    research). It should work out of the box with Fedora Core 4 & 5, and it
    can be made to work pretty easily with FC3 (well it can be made to work
    with any modern Linux distro).
    Linux runs well on both laptops and desktops, but desktops are a bit easier.
    The G4 was faster for a period of time, but even the first Pentium-M's
    would blow it out of the water for most processes.
    I could understand a statement like Apple would never support or assist
    in letting Macs run Windows, but to claim no one would figure out how to
    do it is just plain naïve.
    Well Palm did try putting a HDD in one of their models (LifeDrive), but
    I've heard mixed results. The former TechTV host Leo Laporte mentioned
    buying one on his podcast (This Week In Tech -- twit.tv), and his HDD
    failed with a couple months. When solid state drives get cheap is when
    the PDA realm is going to get really interesting.
    I think he's more of an ivory back scratcher type of guy.
    We shall see. MS has the potential to make some really stupid moves
    with both HDCP (digital copy protection) and TPM ("trusted" computing)
    which could potentially seriously hurt them (esp. with TPM's as that
    could scare off companies). The improvements in virtual machines and
    emulation to allow multiple OS' to run simultaneously also helps Apple a
    lot more than MS. Also I'd say at least half of the current Mac owners
    would buy an Apple as their next machine regardless of anything (a good
    portion of them would buy it just because it looks pretty). Personally,
    I considered a Powerbook (on which I'd probably run either Fedora or
    Gentoo) before I got my D610, but there's too many things that would
    irritate me. Stuff I can't get over is the single mouse buttor, no
    trackpoint, it was a G4 at the time, no good circuit simulation apps
    (like OrCAD PSPICE), etc. Now the last two issues are gone, but I still
    don't think I could get over the mouse.
    Nicholas Andrade, May 24, 2006
  14. Nicholas Andrade

    journey Guest

    That's pretty good. Of course with the Latitude D series one could
    pop another modular battery in if the optical drive isn't needed at
    the same time. It's an interesting experiement. Is that 4 hours with
    the primary battery only? If so that's very impressive. I always
    wished from the beginning that Dell would have included larger primary
    batteries in that series.
    journey, May 24, 2006
  15. Nicholas Andrade

    journey Guest

    Great discussion -- thank you. I could write a lot in response but
    I'll keep it simple and clip a few things here and there.

    This is great news. Eclipse has done a lot for Java. I used My
    Ecllipse for a while.
    I thought so too. He is an amazing instructor though. Watching him
    create Java code on the fly with Jedit was amazing.
    The LifeDrive was a big disappointment. It was slow. It wasn't
    engineered very well. And, as you say next:
    Yep. When the LifeDrive was announced, 1G SD cards were just becoming
    economical for most people. There were uses for a 4G LifeDrive, as in
    storing medical documentation for students and business uses, but as a
    consumer I couldn't justify a slower Palm with a small hard drive.
    Many Pocket PCs had two slots, one for a CF card (approaching 2G at
    the time) and one for an SD card (another 1G).
    I don't know what that means. I don't pretend to know too much about
    him, other than where he was at different times and how his companies
    were doing. He was co-founder of the company of course, was
    instrumental as a visionary for the Mac (according to one book I
    read), after he left the Newton (doomed to failure) failed under
    Skulley (sp) who was assigned to that on his way out. Then he founded
    or got involved with Next, continuing his visions, came back to Apple
    and may or may not have been invovled with the marketing of the color
    iMacs, and iPod. If so, he made up for his serious lacks of judgement
    for the marketing of the Mac in its first several years.

    It's hard to say though. I think Lee Iacocca was just in the right
    spot at the right time and got credit for too much.

    I saw what Apple did with its OS, and how it amazingly seemed to catch
    people by surprise by releasing the Intel-based Macs much earlier than
    expected. Since when has timely and capable implementation been part
    of major OS transitions?

    Palm is at a crossroads with its OS. I can't believe the incompetance
    of execs who let it languish like this. Access, who bought the Palm
    OS, is developing a Linux version. Palm is said to be also developing
    a version of its own.

    Because of Apples success with improving the Mac's OS and for good and
    timely execution (recently), it would have been great for Apple to
    apply that to the Palm. The Palm vs. Pocket PC has many similarities
    to Apple vs. MS. For a long time the Mac OS wasn't multitasking while
    Windows was, just like the Palm OS isn't, while the Pocket PC OS has
    been for a while.
    I'm not so sure. I think it might help Windows for Apple users to be
    introduced to it, realize that Windows isn't that scary, and to enjoy
    the software they can run. I don't see Windows users converting to
    I think the average age of a Mac owner is increasing as the holdouts
    continue to live with their limited machines (OK that's a cheap shot).
    The Mac offers a lot for a packaged solution, but it doesn't take long
    before a Mac owner buys a digital camera or something and discovers
    that yes the OS has some neat multimedia programs, but it doesn't run
    the program that came with my product! Or be put down by friends and
    relatives asking "can your Mac run this game?", "would you like to
    borrow this program? oh, sorry -- that's right, you have a Mac".
    As far as I am concerned the thing the Powerbook did best was look
    good in movie placements. I didn't find the design as good as the
    current Dell notebooks. So what, a sparse metallic slab -- oooh,
    ahhhh, and look at how it doesn't even latch properly and has problems
    with build quality. Oooh, ahhh, I mean ouch!!! Dang, that thing got
    so hot just from checking my e-mail! Oooh, ahhh, heyyy, what
    happened to the money in my bank account? Oh, that's right, I bought
    an overpriced Mac?
    I have heard that the single mouse button issue is going away. My
    mother has had a Mac all these years and I kept her on that because
    that's what my Dad used. I also couldn't get over why they still
    stuck with a single button, and why Apple did such funky things such
    as create a mouse (the whole mouse) which you press down on to click
    it, a Mac cube (I wonder how many hearts were sinking when that was
    unveiled), and the funkiest computer ever -- a PC and monitor in the
    form factor of a desk lamp lol.

    The trackpad supposedly now allows edge scrolling. When I had the
    Powerbook for a while it didn't even do that.

    However, may the force be with anyone who is competing with MS, and I
    will be rooting for Apple even if I think the prospects are dim.

    journey, May 24, 2006
  16. Yes, this is with the primary (6-cell) battery; eunning on those
    settings wouldn't be great for outside work but it should last a flight
    from San Diego to Seattle.
    Nicholas Andrade, May 24, 2006
  17. Hi!
    The D800 seems to be a cool-running machine. About the only part of mine
    that I've noticed getting excessively hot is the memory door on the bottom.
    It did that with the factory installed 512MB and is still the same
    temperature (hot enough to burn at times) with 2GB. Otherwise, it's cool.

    Never noticed any memory trouble then or now, so it's probably by design...

    William R. Walsh, May 27, 2006
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