Test Setup

As stated, we are testing four different operating systems. In order to keep the number of benchmarks manageable, we are focusing on two primary battery life scenarios. Our first test is an Internet web-browsing scenario. We configure the chosen browser to load three websites that contain Flash content every 60 seconds. When the battery level goes critical (usually 1%, although Windows 7 doesn't let us set this lower than 3%) the system shuts down. The second test is DVD playback battery life, again with the system set to run until the battery level is critical. The various operating systems don't necessarily give you the same level of control over power saving features, so we tested a couple scenarios on each Windows OS.

Windows XP

Windows XP gives you the least control over power saving features. We test two scenarios, one using the Portable/Laptop profile and the other using the Max Battery profile. We don't have specific details on what these settings mean in terms of maximum CPU performance, but it's clear that they do affect performance. They also impact battery life, and most people only want enough performance when running on battery life for their system to work properly. We did not experience any difficulties watching DVDs or surfing the Internet, although more CPU intensive tasks may have problems when using the Max Battery profile. On the Portable profile, the HDD is set to power down after five minutes, while the Max Battery profile has it set to power down after three minutes. We also measure LCD brightness with a colorimeter and set it as close to 100 nits as possible.

Windows Vista/7

Similar to Windows XP, we test two different power profiles in Windows Vista and 7: Balanced and Power Saver. These profiles correspond roughly to the same settings as the Windows XP profiles, but this time we have more control over the various details. For Windows Vista and 7, we use the following settings under Balanced.

The hard drive is set to power off after five minutes. The wireless adapter is set to medium power saving, hybrid sleep is enabled, and USB selective suspend is enabled. PCI-E link state power management is set to maximum power saving. The minimum processor state is set to 5% and the maximum processor state is 100%; we don't know how this specifically affects CPU clock speeds, and if you want to run a similar test make sure your notebook manufacturer doesn't specify different values. Search and indexing is set to power saver and adaptive display is disabled. Again, we calibrate the LCD to run at 100 nits, which is 35% brightness for these two laptops (three steps above minimum brightness).

The Power Saver profile uses the same settings in most areas, but we set the hard drive to power down after three minutes, the wireless adapter is at maximum power saving, and the maximum processor state is 50%. Windows 7 does include a few other areas that you can tweak, but most of these relate to LCD dimming in order to conserve power. This is not to say that Vista and Windows 7 are the same, because as we will see in the results there are some definite differences.

Ubuntu 9.0.4 (Jaunty)

There aren't a lot of power saving features available for tweaking within Linux - at least not that I could find. We configured the LCD to never shut off (just like on Windows), and set the system to shut down at 3% battery - the minimum we could specify. We also disabled LCD dimming. Honestly, I don't know nearly as much about Linux as Windows, but I did my best to get Linux installed properly on the two notebooks. As anyone who has used Linux before can tell you, getting driver support is sometimes a real pain in the rear.

Generally speaking, both systems also felt far more sluggish running Linux, especially for typical web browsing. We used Firefox 3.0 initially and then updated to 3.5 - not as easy as I would like under Ubuntu, and I have no idea why the latest build is called Shiretoko in some places and Firefox 3.5 in others. Whatever. Both versions of Firefox felt incredibly slow, but that was with Flash enabled. With the FlashBlock add-on, Internet performance was significantly better, but that isn't a fair comparison to the Windows browser tests. As a point of reference, we ran the same test under Windows Vista and achieved significantly better battery life. We will get to those results in a moment.

Our issues with configuring Ubuntu don't end with the browser, however. On the Intel-based NV58, we could not get LCD brightness to function properly. The result is that the LCD ran at maximum brightness during our tests, which obviously results in lower battery life. We tried to find an updated driver for the Intel GMA 4500MHD graphics, but so far we have been unsuccessful in addressing this issue. The AMD-based NV52 wasn't any better, but for different reasons. We could find updated drivers from ATI, but after repeated attempts we never did get them to function properly. We were left with running the proprietary fglxr 8.600 driver, and while it worked fine in general we had problems with DVD playback. VLC repeatedly crashed during our benchmarks, sometimes after a few minutes, sometimes after 50 minutes. Eventually, we decided to uninstall the proprietary ATI driver and test out the open-source MESA driver. Surprisingly, the open-source driver actually provided a better experience, although we aren't looking at 3D performance where ATI's fglxr driver likely has an advantage.

The short story is that while everything eventually worked out okay on the NV52, the number of headaches we encountered trying to get everything working properly under Ubuntu is more than a little frustrating. You get a sense of accomplishment once everything is working, or at least I did, but that's not something most people are interested in doing. Most people view computers as a tool and they wanted to "just work"; they don't want to scour the Internet looking for instructions on how to manually install the latest drivers/application/whatever. If you're Interested in a more detailed look at Linux, we suggest you read our Ubuntu 8.04 Article. The only area of Linux that we're testing today is battery life.

Index Gateway NV52 (AMD) - Battery Life


View All Comments

  • aahjnnot - Tuesday, September 22, 2009 - link

    I can't see what software was installed on the laptops. Real-world system performance is affected adversely by the installation of everyday software, and it seems highly probable that this would also affect battery life, startup times and suspend / resume / hibernate performance.

    It would be very interesting to see a real-world test to understand whether different operating systems are more or less affected by the cruft of daily computing. I'd suggest including anti-virus, an internet security suite, an office suite, Skype, Windows Messenger, a couple of games, itunes or equivalent, some printer drivers, some backup software and a camera management application.
  • JarredWalton - Tuesday, September 22, 2009 - link

    The installs were all "vanilla", though I updated DirectX and installed the tested Futuremark suites on the Windows setups. In all cases, there were no Firewalls or AV software enabled. I disable automatic updates, firewall, Defender, indexing, screen savers, and set a static swap file size of 4GB. I do not try to disable any extra services, but I try to avoid any extra apps loading at start up (i.e. system tray icons that serve no real use).

    For Ubuntu, I just did the basic install and then tried to make it work. Easier said than done for a few areas. LOL. I manually added package repositories for Firefox 3.5, some drivers, and the necessary things to get DVD playback working. Far from a trim and speedy install, I know, but it's what Ubuntu uses by default, which means it's what most Ubuntu users will use.
  • aahjnnot - Tuesday, September 22, 2009 - link

    I can understand why you chose a vanilla installation, but it means that your results are hardly representative of the real world. All Windows laptop users will need anti-virus; most will have a raft of additional software; and few will disable system tray entries.

    I run both XP and Ubuntu 9.04 on my laptop and on a couple of boxes at home. In all cases Ubuntu starts up significantly faster than Windows, and that's because cruft seems to affect Windows more than it does Linux - on my machines, a vanilla Windows installation is fast but unusable as it's insecure and has no applications.
  • stmok - Tuesday, September 22, 2009 - link

    Which guide did you follow? Reply
  • JarredWalton - Tuesday, September 22, 2009 - link

    This was the guide I found for the ATI platform:

    If their own BinaryDriver guide doesn't work, I don't have much hope for other alternatives!
  • stmok - Wednesday, September 23, 2009 - link

    Hmmm...I see. Looking through the link you've provided leads to...

    Fix Ubuntu 9.04 ATI Driver Issue
    (This isn't a fix...Its merely being accommodating to the closed driver's deficiencies.)

    Essentially, you want to stay away from ATI hardware until the open source community completes their work on the open driver for ATI solutions. ie: Waiting for xf86-video-ati driver to support your video solution. (Which will take quite a while! They're making slow progress.)

    Generally, I research/pick my hardware BEFORE I install Linux. Sticking to Intel and Nvidia based solutions work best. Although, certain Intel IGPs like the GMA 500 is poorly supported. (Intel only provided a closed source driver for that particular solution).

    Of course, one also has to understand that Linux is undergoing a major graphics stack re-write. (They are replacing three old components with one)...The initiative is being led by a few Intel employees and Xorg developers. This will affect recent Intel IGPs like the GMA 3xxx, GMA X3xxx and X4xxx series.

    So I guess something like the Intel GMA900/950 IGPs or Nvidia supported solution are the ones to go for.
  • gstrickler - Tuesday, September 22, 2009 - link

    Here are the conclusions I draw from this article:

    1. Anand/AnandTech will admit when their testing procedures are inadequate. Always a sign of a good researcher. Thanks, looking forward to updates when you find a more repeatable set of for "internet battery life"

    2. Win 7 drivers may still need tuning for performance and/or battery life.

    3. Win 7 battery life improvements are not likely to be the 30%+ that some vendors are claiming. You might get that much best case, but typical results will be much lower.

    4. Vista sucks. Use XP or Win 7 instead.

    5. Flash sucks. Ok, Flash is actually cool and useful, but it's implementation sucks. Adobe has never been known for small, fast, or efficient code.

    6. Currently, Intel beats AMD in power usage/battery life.

    We already knew #4-#6, and suspected #1-#3. The good news is this confirms what we already knew or suspected. The bad news it that it doesn't give us much new information.
  • andrewaggb - Tuesday, September 22, 2009 - link

    Well I found a couple things interesting, power profiles matter but not necessarily as much as you'd think.

    And it had never occurred to me that disabling flash would give way better battery life. It makes total sense, but without the article I wouldn't have thought of it.

    Otherwise, I agree with your analysis of 1-6

    I think the actual numbers are pretty questionable, but the author admits that there is a wide variance.

    Otherwise I found the linux results amusing, as well as the comments. We can only hope that people who work for canonical actually read these reviews and work to improve the usability of their products.
  • maveric7911 - Tuesday, September 22, 2009 - link

    Of All linux distributions to use, ubuntu has so much bloat its no wonder its eating battery like that. Please use other distributions out there rather then giving the same old ubuntu bloatware benches. Reply
  • MonkeyPaw - Tuesday, September 22, 2009 - link

    "The minimum processor state is set to 5% and the maximum processor state is 100%; we don't know how this specifically affects CPU clock speeds"

    It's actually pretty simple, and the feature only works with CPUs that have Powernow or Speedstep. The "Maximum Processor state" is how fast the CPU is allowed to run when the system experiences high-cpu load (which would normally increase CPU speed). For example, if you have the maximum set to 50% and you have a CPU that runs at 2.0ghz, Windows will limit the clock speed scaling to what ever multi gets it closest to 1.0ghz. I have my Toshiba notebook limit my 2.1ghz Turion X2 to 50% (1.0ghz) while unplugged to conserve battery power. Note that these percentages are not an exact science, as it's all dependent on the predefined power states (available multi's) of the CPU you're using. It is, however, a way to improve battery life if you don't mind slowing the system down a little. Personally, I don't need that much power while unplugged, but in the rare occasions that I did, I could always change power plans from the battery icon in the taskbar.

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