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

  • PrinceGaz - Tuesday, September 22, 2009 - link

    When surfing on my iTouch, I find that the vast majority of websites display almost the same (complete with images) despite the lack of Flash, and Java as well for that matter (it does at least support JS). There are just the odd undisplayed areas which in most cases are where I know ads would be normally. A very few websites use Flash for navigation and content display without any alternative version of the site available, but the overwhelming majority of sites display fine.

    That being said, I would prefer to have the option to enable Flash and/or Java if I wished, but would probably leave Flash off most of the time given the likely impact it would have on battery-life and overall responsiveness.
  • strikeback03 - Tuesday, September 22, 2009 - link

    Is there a way to force a mobile version of ESPN that still displays all the links that are flash on the main site? Reply
  • emboss - Tuesday, September 22, 2009 - link

    For day-to-day browsing I have flash turned off. Even on Windows it speeds things up, and as a bonus kills most of the ads that try and get around ad blocking. Excluding YouTube videos, I maybe have to enable it once a month or so to use a site that's broken enough to require it.

    Then again, I use the internet for information rather than entertainment, and things like MSDN don't require flash :)
  • sc3252 - Tuesday, September 22, 2009 - link

    Flash isnt really a part, you can view most sites without it. The only sites that really need it are those crapy sites you really dont want to be at.
    Another nice point to make is how poorly optimized flash is for GNU/Linux. I am not surprised when using firefox without blocking flash you get such lower battery life since there is almost no acceleration on GNU/Linux. With a 3.2ghz core 2 I can't watch fullscreen flash without skipping and jerking on Debian testing.
  • pcfxer - Tuesday, September 22, 2009 - link

    With my 2.9GHz Athlon X2 5000+ BE, 4GB RAM on PC-BSD 64-bit (with the stock nvidia drivers), I am able to view full screen HD flash without a hint of trouble. This is handled via binary emulation of Linux running Firefox linux with linux flash plugins.

    Perhaps, anand could test a REAL Unix-like OS and try out PC-BSD. It is MORE "free" than Linux (GPL).
  • pcfxer - Tuesday, September 22, 2009 - link

    I realize that some people may mistake this "REAL Unix-like" for seriousness, it is a joke btw. That said, I am serious about testing PC-BSD - I am a tester for them anyhow ;). Reply

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