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

  • JarredWalton - Tuesday, September 22, 2009 - link

    I'll look into powertop in a while. The issues with Windows really have a lot more to do with users than with the platform as a whole. My work PC has been running without any problems and without reinstalling the OS for over three years. My gaming system is in a similar state, and both have been through a few hardware upgrades, plus various driver and software installations.

    I don't run any "internet security suite" - be it McAfee, Norton, AVG, or anyone else. No AV, not even anti-malware (though I have scanned with Spybot S&D, Ad-Aware, and HiJackThis on occasion just to make sure). Why am I problem free? Because I know what I'm doing.

    I think the same could be said of Linux users: they're mostly problem free because they know what they're doing, and they could be problem free in Windows if they wanted to put in a small amount of effort.

    Put your average user in front of a Ubuntu installation -- or any Linux installation -- and they're going to be lost as soon as they want to do more than run email, OpenOffice, and surf the Internet. "But that's all you need!" Exactly: all you need and all you want are not the same. Windows makes it perhaps too easy for people that haven't got a clue to install programs and screw things up. LOL
  • Gamingphreek - Wednesday, September 23, 2009 - link

    Honestly, all the configuration I suggested takes a few minutes at most. There is no compiling from source and no generating makefiles.

    As someone said earlier, Linux and Windows have different philosophies in terms of setup. Linux is an OS that depends on customization, at least SOME time needs to be put in configuring it.

    Running powertop and writing a bash script takes a mere 5 minutes and can save >30 minutes of battery life in some cases. Enabling laptop mode is literally as simple as opening a file and changing the value from 0 to 1.

    Updating the kernel, mesa, and graphics is literally 6 (2 for each -- 1 to add the repository and 1 to add the key) commands long and takes <5 minutes.

    I understand this isn't an article on Linux, but these are not in depth tweaks and are things that anyone running Linux on a laptop will typically do.

    Finally, you state that an average user would be lost in Linux. Honestly this is Anandtech - a very well known and reputable Tech based website. "Average users" typically do not venture here. Should you guys stop talking about Processor Architecture since people wont know what it means?
  • strikeback03 - Wednesday, September 23, 2009 - link

    My father needed to move suddenly due to a job change, so I hooked him up with a computer I scavenged out of the trash at work. It had a XP license key on it, but thanks to their wonderful restrictions on what what disc can install what version I had no working installer for that key. So I threw Ubuntu on there, which does indeed do everything he needs (allow him to play with his investments and watch Hulu). He called last weekend asking where to find a driver for a printer that was not included by default, as the solution involved several lines of code he decided to just wait until I can walk him through setting up Remote Desktop and do it from here. Reply
  • Mattus27 - Monday, September 21, 2009 - link

    I can't believe you tested using live dynamic websites, instead of just downloading a page and all its resources and running the test from disk. The drawbacks of that should have been fairly obvious. Reply
  • JarredWalton - Monday, September 21, 2009 - link

    The problem is, there is a ton of JavaScript involved with any current website, and getting all of the content for an offline version isn't quite that simple. Go try it: download everything for www.AnandTech.com to your PC and then look at that file and compare it to how the site actually looks. Try that with Facebook, YouTube, Yahoo, MSN, CNN, HardOCP, FiringSquad, SlashDot, TechReport, etc. and you will find they all need tweaking to look anything approaching correct. (Well, maybe not every single one of them, but most will still end up with JavaScript files that load content from dynamic web servers.)

    Anyway, I wanted to test with "real" content and not some bogus artificial test that doesn't have anything to do with what real Internet sites are like (i.e. some of the MobileMark stuff has very questionable testing procedures). I wanted something I had control of that would still tax PCs like a real website. I've got some downloaded sites and I've been going through the HTML and modifying it to hopefully create a "static" page that I can host on our server and still have it work more or less correctly. That of course means another batch of testing, but so far it's looking good.

    I debated scrapping the current article, but figured some would enjoy the read and the joys of testing multiple different OSes. Besides, this way I can get feedback on what other tests you might like to see.
  • gstrickler - Friday, September 25, 2009 - link

    How about setting up a local caching web proxy and having all the machines connect via the proxy? It won't completely eliminate the variances of internet routing/throughput and connecting to live sites, but it should minimize them.

    As for Wi-Fi (and interference from your 2.4GHz phone), leave the Wi-Fi enabled and connected, but go ahead and connect the machines using Ethernet. The difference is drain of a modern Wi-Fi transceiver when transmitting/receiving vs "idle" is fairly small, so simply having it on and connected to the Wi-Fi access point (which will occasionally "talk" to each connected client") should be sufficient from a power draw standpoint while using Ethernet for the active network connection will be more reliable and won't be subject to the interference. You can put the Wi-Fi on a subnet that does not route to your proxy/firewall and/or give it no default gateway, which will ensure that all the real traffic in on Ethernet. You could add in an occasional Ping from each client to the WAP to ensure that the Wi-Fi card/connection stays active.

  • andrewaggb - Tuesday, September 22, 2009 - link

    Well I certainly agree that testing dynamic websites at different times is not the way to go.

    I can also understand what you are saying about trying to download a site and all the related resources, I've tried in the past and the browser method doesn't work.

    You'll probably need an external tool to download the site and all it's resources. A quick google search came up with this tool, http://www.surfoffline.com/">http://www.surfoffline.com/, I've never used it but it has a trial and it sounds like you can download entire websites and export them. Worth a shot anyways, there's probably a bunch of tools like this that "hopefully" work as advertised :-)

  • Lowly Worm - Monday, September 21, 2009 - link

    ".. we ran the same test under Windows Vista and a cheat significantly better battery life. "

    Heh.. DragonSpeak "a-cheating" on you? Makes for interesting phonetic typos.
  • JarredWalton - Monday, September 21, 2009 - link

    Yup. Thanks for the correction - was supposed to be "achieved", naturally. :) Reply
  • lordmetroid - Monday, September 21, 2009 - link

    The Linux distribution you tested while mainstream, maybe not as tailored to mobility as say the Moblin distribution by intel, though still in Beta, I would loved to have seen that distribution tested considering it is specially built with focus on mobile platforms. Reply

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