OS Mobility Explored

by Jarred Walton on September 21, 2009 6:00 PM EST

Gateway NV52 (AMD) - Battery Life

We'll start with AMD's mobile platform, which we have already dissected in previous reviews. Here's the quick rundown of specifications, and as much as possible we updated all applications, drivers, and OS components to the latest versions. The ATI drivers for Windows XP and Windows Vista are slightly older than the Windows 7 drivers, but unfortunately we are not able to install "reference drivers" on ATI-based laptops for Vista or XP. Thanks OEMs!

Gateway NV5214u Test System
Processor AMD Athlon 64 X2 QL-64
(Dual-core, 2.1GHz, 2x512KB L2, 65nm, 35W, 667MHz FSB)
Memory 2x2048MB Hyundai PC2-5300 @ DDR2-667 5-5-5-15
(Hyundai Electronics HMP125SEFR8C-Y5)
Graphics Integrated ATI Radeon HD 3200
Driver version Cat 8.582-090203a (Feb 03, 2009)
40 (8 x 5) Shaders at 500 MHz
Display 15.6" Glossy WXGA (1366x768)
AU Optronics B156XW02
Hard Drive Seagate Momentus 5400.6 320GB 5400RPM 8MB (ST932032 0AS)
Optical Drive 8x DVDRW (LG Electronics GT20N)
Battery 6-Cell 10.8V, 4400mAhr, 47.5Whr
Operating System Windows Vista Home Premium 64-bit
Price NV5214u available at Best Buy for $500

We are comparing performance and battery life on a single system, so system specifications don't necessarily matter. This is an apples-to-apples comparison between several different operating systems using the same hardware. Here are the results.

Gateway NV52 Internet Battery Life

Gateway NV52 DVD Battery Life

So we have some good news and some bad news. The good news is that Windows 7 definitely shows some battery life improvements relative to Windows Vista. The bad news? We're still awaiting the official launch of Windows 7… and then we need to start from scratch with battery life testing on future laptops, since as we don't want to compare apples and oranges.

Using the Balanced profile, Windows 7 ends up providing 11% more battery life than Windows Vista. When we switch to the Power Saver profile, the margin of victory shrinks to 5%. The wildcard in these tests is Windows XP, which delivered the best battery life using its Portable/Laptop profile (by 2% over Win7, so it's almost a tie). However, it also achieved the worst battery life using the Max Battery profile (Win7 wins by 6%).

The margin of error between runs is around 3%, but we try to run each test multiple times and take the best result… unfortunately, when you have one laptop and about 30 battery tests to run on it, each requiring around four hours (with recharge time), repeating each test is a bit too much to ask for. Case in point, the Gateway NV52 originally had a score of 175 minutes on one run with the Power Saver profile, which seemed too high; rerunning the test three times showed that there must have been some other factor involved (i.e. perhaps a Flash ad server was temporarily down). Feel free to take the figures with a grain of salt, and we have some additional data later to verify the standings.

Clearly, power profiles are making a big difference depending on the operating system. Windows XP saw the least benefit, improving just 4.5% by using the power saving profile. Windows 7 comes in second, with an improvement of 13%. Then we have Windows Vista, which delivers an astounding 20% improvement in battery life just by switching the power profile.

Ubuntu is a little bit more difficult to assess, but clearly Ubuntu doesn't come anywhere near matching Windows. Using the power saver profile and Firefox, Windows Vista beats Ubuntu by 38%. Even if we factor in the power profile (Ubuntu doesn't appear to have a way to manage power profiles like Windows), that would still be a difference of around 15% in favor of Vista. Flash is extremely sluggish on Linux, however, and the margin of victory decreases when we use the FlashBlock add-on. At that point, Windows Vista only wins by 19%, which we could attribute to the power profile. That's still a significant difference in battery life, and we're using the worst of the Windows OS options for comparison. We didn't have time to test with other operating systems using Firefox or FlashBlock, largely due to the amount of time we spent trying to get Ubuntu to work properly in the DVD playback results.

The DVD playback results are completely different from the Internet battery life results, with the power profile having virtually no effect on battery life. The three Windows versions had the same score, within one minute, using each profile, so using the Power Saver profile is clearly no panacea. On the other hand, there are definite differences between the three Windows OSes. Ubuntu crashed repeatedly during DVD playback, sometimes to the point where we needed a hard reboot. Changing to the open-source MESA drivers fixed the situation with DVD playback, but under that test scenario Ubuntu manages a rather unimpressive result. It looks like ATI's drivers would last just over two hours with Ubuntu in DVD playback, so they definitely do better in terms of power optimizations. Looking at the Internet battery life with the open-source MESA drivers, there's clearly a lack of power optimizations (despite enabling dynamic clocks in the xorg.conf file).

Overall, Windows 7 appears to improve battery life for DVD playback by over 20% relative to Windows Vista, but the improvement is only about 6% relative to Windows XP. The story for Internet surfing is far more confusing. If you use the Balanced power profile, Windows XP beats Windows Vista by 13% and just edges out Windows 7 by 2%, making it the best option. Turn to the Power Saver profile and Windows 7 is the leader, 6% ahead of XP and 5% ahead of Windows Vista. Ubuntu isn't even in the running, with Vista offering up to 37% more battery life using Firefox; blocking Flash elements does help Ubuntu, but it also helps Windows and the gap shrinks to only 19%. Makes you wonder if Flash content is actually worth having, doesn't it?

Test Setup Gateway NV52 (AMD) - Futuremark
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  • ascl - Tuesday, September 22, 2009 - link

    I was reading this thinking that it was an unusually bad review from anand.... then I reached the conclusion 2 + 3 and my complaint was answered! Using randomised web testing is terrible if you want repeatable results. Use an internal server with a fixed set of pages (and ads).

    Kudos!
  • vailr - Tuesday, September 22, 2009 - link

    Maybe compare battery life on a MacBook Pro running OSX Snow leopard vs. Windows 7 64-bit/Win XP 32-bit (in Boot Camp) vs. Ubuntu(?). Using VLC Media Player sequenced to play a series of several DIVX movies, for finding the running time under each OS.
  • gstrickler - Saturday, September 26, 2009 - link

    Anand has already done that with a MBP and OS X vs XP (and maybe Vista). Anyway, it would be good to see it repeated with Win7 in a couple months when they've had time to produce some reasonably power efficient Win7 drivers.

    In any case, a MBP is a great platform for the task, it will run all those OSs, the Nvidia chipset is well supported in all of them and it's pretty power efficient. Of course, with it's battery life, the tests might take a while.
  • Gamingphreek - Tuesday, September 22, 2009 - link

    Battery life in Linux, as it is a *nix based OS, needs configuring. You claimed that you couldn't find it, but honestly you need to find someone who has *nix experience then because it is honestly the most customizable of the OS's.

    Additionally, while you did a good job in following that website for advice, staying with the 'Safe' configuration is a grave error. All that merely does is use an old version of MESA (OpenGL driver) and an old Intel driver. I would honestly like to see you try out the 2.6.30.5 or the 2.6.31rc kernel along with the most up to date drivers from the XorgEdgers repository. Performance with those optimizations is honestly quite remarkable.

    Furthermore, I would suggest looking over lesswatts.org as well as running the PowerTOP application to see what is unnecessary. For instance, I have a script that disables my PCMCIA slot given that I do not use it. I also have my RJ11 based modem disabled. I have LaptopMode enable automatically when I unplug A/C power and disable when I plug in A/C power.

    Additionally, why did you turn off auto dimming?? That is a great feature that severely crippled the performance of Ubuntu yet again.

    As for Firefox/Shiretoko (Shiretoko is the codename for Firefox 3.5) that is a known issue with lazy programming. Downloading the Noscript or Adblock extension helps immensely with performance. Additionally Shiretoko/FF3.5 has a vastly improved engine when compared to FF3.0.

    Additionally, I don't believe you stated what file system you were using. EXT4 is vastly superior to EXT3 (While it isn't the default, among Linux users, it is rare for someone to choose EXT3 over EXT4) - especially when boot times are involved. Even still, it sounds like there was a broken script or something - Ubuntu 9.04 has the fastest startup/shutdown I have ever experienced.

    Honestly, Ubuntu seemed to draw the short end of the stick here. It takes time to configure the OS - I honestly expect more time to be given to configuring it like the other ones.
  • smitty3268 - Tuesday, September 22, 2009 - link

    While I agree with most of your points (you can definitely tweak linux down to the bare bones much more than something like XP to save power), I think it is perfectly acceptable to use a default distro that is commonly used. After all, he didn't go through the Windows registry, disabling services and hacking stuff there either.

    But in the end, let's face it. Firefox and Flash are horribly optimized for Linux. It's not exactly a surprise that they suck down more juice, given that they usually take about 5 times more CPU power than under windows.
  • Gamingphreek - Tuesday, September 22, 2009 - link

    Well that is the inherent difference between Linux and Windows.

    Thats like saying you aren't going to download and install drivers for Windows - Linux comes with all of them...

    And as a slight correction, Firefox isn't really the problem and Flash is horrible for any/everything BUT Windows.
  • JarredWalton - Tuesday, September 22, 2009 - link

    As stated, it wasn't intended to be a Linux review. This is a well-known Linux distro that is supposed to be "easy". I don't have the time nor inclination -- just like 99.9% of users -- to go into detailed steps for hacking and modding Linux. I fully understand that it is highly customizable, but so is a car if you're inclined to go that route. I drive a stock vehicle, and I use a stock OS.

    Downloading drivers isn't the same thing as downloading the latest kernels, creating your own conf files, and manually entering all sorts of settings that help enable/disable items to provide better power saving. My conclusion pretty much sums up my feelings: the out-of-box experience for Ubuntu is nothing special for a laptop, and if you are expecting it to "just work" you'll be disappointed.

    Given how much is available for tweaking in the Linux community, I'm frankly surprised that no one has apparently spent the time to make the default configuration far more sensible and easier to live with. I know how much fun it is to download and compile programs and edit configuration files, but I'd rather just have an easy interface that works without a ton of effort.

    I also fully recognize the inherent problems with Flash, so I put in numbers with Firefox and FlashBlock. It helps, but it doesn't help enough to equal the default Windows setup. There are other browser options of course, and if/when I get time I'll see about looking at some of them.
  • ekul - Tuesday, September 22, 2009 - link

    Ubuntu is a poor distro for battery life out of the box as many of its default settings belong on a desktop or even server system. With a bit of tweaking though it can easily get better battery life then windows. My netbook struggled to get 2 hours in XP, in ubuntu I can easily see 2:45 or more.

    As has been mentioned by at least one other commenter use the powertop tool (sudo apt-get install powertop && sudo powertop). This was written by intel to help find applications and drivers that were waking up the cpu too much and hurting battery life even if they didn't appear to be using very many system resources. The tool itself looks for many settings that are not optimal for battery life and offers to correct them for you so you don't have to go on a treasure hunt at all. I'd love to see what kind of improvement could be made with that tool alone.

    As an aside, a major oversight is idle battery life. All of your tests feature the OS as the minor player in the war against power consumption. In each test you have an application eating the majority of the resources. You should fully charge the battery and let the laptop idle at the desktop until it dies, testing each OS's ability to sleep long running processes and services. Perhaps leave an office suite, browser idling on a page and wifi connected to stop the runtime for taking too long.

    Finally using flash heavy websites heavily skews the results for both OS and browser battery life tests since you are sending both into battle missing limbs. It is well known flash is poorly written software at the best of times, causing well over 60% of all firefox and IE crashes. It has rudimentary 64 bit support, doesn't support hardware acceleration on anything but windows and if it isn't playing video (covered by the dvd test) is almost certainly on the page to serve an ad. No browser has any sort of control over flash (though chrome does its best to reign it in) so your browser tests amount to little more then a test of flash. Flash sucks even in windows but in linux it is truly awful (as is almost all closed source code for linux).
  • JarredWalton - Tuesday, September 22, 2009 - link

    The second batch of sites was hardly Flash-heavy. Yahoo and MSN have one Flash ad, YouTube has none, and the Facebook login page is just text and images.

    FWIW, I did run an "idle at desktop" test on Ubuntu on the NV52 and got a time of 204 minutes. That compares to 242 minutes under Vista, or a 18.6%. There are a LOT of other things I still need to look at, however -- including different power schemes, tweaked profiles, etc.

    If I'm going to try to improve the Linux results in every way possible, it's only fair to do the same for Windows.
  • ekul - Tuesday, September 22, 2009 - link

    Because the linux and windows philosophy is so different a different approach has to be taken to setting them up and running them. With windows initial setup is very simple and has vendor support for things like drivers. Over time problems begin to appear and cleanup/formatting becomes necessary. Most linux distros integrate all possible hardware support and target lowest common denominator hardware to ensure broad compatibility at the expensive of performance. Once they have been tweaked they will continue to run indefinitely at that level.

    With windows you have ease now for pain later. With linux you have pain now for ease later. This means running things like powertop and changing the init options to run in parallel would be the same as cleaning a registry in windows rather than something like disabling services in windows. I spent one afternoon tweaking my netbook and now it runs much smoother and faster then it ever did with windows plus the battery life is longer. Changing config options and customizing for your hardware is the reality with linux the same way random problems cropping over time is the reality with windows. If linux distros are to be punished for ease of setup issues then windows must be punished for altered performance 6 months from now. Linux is getting better however, and different distros ship with very different defaults. Ubuntu is really debian unstable repackaged for the server/desktop which means at its very heart it is a server distro. For future tests opensuse may be the best choice to represent laptop/desktop defaults.

    FWIW if you want to find the real options in linux for power management you should look in /sys/devices/system/cpu/cpu0/cpufreq/. The options in the gnome power management panel only really deal with monitors. But again 3 minutes with powertop and I'm certain you will see an improvement.

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