Battery Life and Windows 7

Discussion in 'Windows, Linux & Others on the Mac' started by ryannazaretian, Dec 28, 2009.

  1. ryannazaretian macrumors 6502a


    Sep 21, 2008
    This will be a thread to try to get better battery life on Windows and the problems that we face. My system is shown below, and by design, I'm supposed to get about 5 hours in OSX. I currently have a a 2.89% wear on my battery after a year (44670/46000mWh).

    First of all, I get about an hour and a half on Windows 7 without any special tweaks while being online. I'm running on Power Saver, and have all extra software turned off. The computer remains fairly warm the whole time while running in Windows. What I want to try to do is pinpoint problems with our current setup.

    So, first off, definitely close any unneeded programs. If you're not using the internet, turn the card off (Cmd + X and press "Turn wireless off") Disable your antivirus since there should be no need when off the net. Turn the brightness down to the minimum that you need to see, and turn down the keyboard light. Update your drivers. The one's that Apple provides on the disk are way out of date. Newer ones should yield better reliability, higher performance, and lower power consumptions. Also run your computer in Power Saver mode; this will switch off Aero. Those are the simple things.

    With all of this done, I can get nearly 2 hours of battery life in Windows.

    I did a quick check of what is using up system resources by going to the Command Prompt and typing "powercfg -ENERGY" and letting it run for 60 seconds. It will save a log file in your user folder. I found some interesting things, and most of it has the finger pointing at Apple and possibly Nvidia's Chipset drivers.

    A lot of the errors in the log are talking about the USB Root Hub and USB Composite Device. Keep in mind that I have nothing plugged into the computer. The problem with all the USB Devices (8 total) is that it cannot suspend the devices. Another problem is high CPU utilization by Bootcamp.exe. I have the priority of Bootcamp.exe set to low and only allow it to run on CPU 1 (As per Timur's DPC Latency fix.)

    Here are some problems right now:
    You cannot switch off Bluetooth. I find this to provide more battery life in OSX, so I would like to do this in Windows.
    You cannot switch the Nvidia graphics cart to power save mode, or use the 9400m graphics card.

    Currently unknown to me. Why is this laptop as hot as it is when idle? It should be cool to the touch like in OSX. My CPU remains around 0% all the time in Windows, so it should not be CPU utilization that is eating up the CPU. Nothing even remotely intensive is running. All I have is Firefox running.

    Maybe we'll see something good when Apple releases the Bootcamp update within the next few days if they keep to they're schedule of late 2009.

    So as a conclusion. Has anyone found any amazing tweaks to get longer battery life or make it run cooler? Registry tweaks? Tweaked drivers? Software?
  2. balamw Moderator


    Staff Member

    Aug 16, 2005
    New England
    I believe that is the main reason, the power hungry GPU is always on full bore.

    The easiest way to get more battery life is simple. Stay in OS X. :p What are you doing in Windows with the CPU idle that you can't do in OS X.

  3. ryannazaretian thread starter macrumors 6502a


    Sep 21, 2008
    School work using Visual Studio 2008. I know... Xcode, but I got in trouble using it last year. The compiler is different. Xcode took what I wrote just fine, but it wouldn't compile on Visual Studio. But that's getting off topic. I really want this thread for people to share ways to improve battery life, maybe go a little deeper than all the other threads. Post some real down and dirty gritty stuff.

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