OS Mobility Explored

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

For the past couple of weeks, we've been running tests on a few laptops to investigate how various factors impact battery life. Our first article looked at browser battery life, and the results were interesting to say the least. Most browsers were relatively close, but the use of websites with Flash content tended to tip the scales in favor of Internet Explorer. We have more tests in store today, this time looking at battery life with different operating systems along with other aspects of day-to-day OS use.

Representing the Microsoft camp, we have the venerable Windows XP SP3, our current standard of Windows Vista 64-bit SP2, and the up and coming Windows 7 64-bit RTM. Not too fond of Microsoft operating systems? We've got you covered there as well, with benchmarks using Ubuntu 9.0.4, although it shouldn't come as much of a surprise that we encountered some difficulties getting Linux configured properly. We'll have more to say about that in a moment. This isn't a Linux/Ubuntu review by any means, as we're just looking at the out-of-box experience with as little tweaking as possible. If you're running Linux on a laptop, though, the results will be… enlightening.

Our two test laptops from Gateway make another appearance, the AMD-based NV52 and the Intel-based NV58. These are both entry-level laptops, but more importantly they both use integrated graphics so battery life is actually reasonable. If you have a high-end laptop with discrete graphics, changing your operating system isn't likely to make nearly as big of a difference. We've already compared performance of the two Gateway notebooks, so the focus here is going to be on how much of a difference the operating system can make. We did use the same settings where possible, so you can also make comparisons between the two platforms if you so desire. However, our general opinion hasn't changed with the use of different operating systems.

If your focus is on battery life and general performance, the Intel-based NV58 is clearly superior. On the other hand, AMD's integrated graphics are typically twice the speed of Intel's GMA 4500MHD, so users interested in gaming/graphics and video decoding might be better served by the AMD setup. Then again, if you want the best of both worlds - high-performance and improved gaming performance without compromising on battery life - you might be interested in spending more money. We have a review of Dell's Studio 14z in progress, which uses an NVIDIA GeForce 9400M graphics paired with an Intel CPU. Yes, it's more expensive - potentially a lot more expensive! - than both Gateway system, and it doesn't come with an optical drive, but it provides better performance than the NV52 and NV58 and similar battery life to the NV58. Sometimes you get what you pay for.

Besides looking at battery life, we are also going to provide a few quick benchmarks under the three Windows operating systems. These are not comprehensive benchmarks by any means, as we simply ran the various Futuremark 3DMark/PCMark tests suites, but they do provide a point of reference. In addition, we'll be looking at common day-to-day OS tasks like the time to boot/shutdown, hibernate/resume, and sleep/wake. If you're curious about which OS is the fastest and best suited for use on a laptop, this article should provide some answers - and perhaps a few new questions as well.

Test Setup
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  • JarredWalton - Tuesday, September 22, 2009 - link

    I don't think it works quite like that. If you set it to 0%, I believe that's the minimum CPU speed (i.e. 5.25 x 200MHz on the NV52 and 6 x 200MHz on the NV58), while the higher percentage may try to target a maximum speed. 100% would be the normal CPU speed, but would 50% be half-way between minimum and maximum?

    I'd have to investigate more, but I do remember testing with CPU-Z and seeing CPU clocks go well above the 50% mark. I think at best it's approximate, as you suggest, and how accurate it is likely varies greatly with the CPU - and even BIOS options.
  • trochevs - Tuesday, September 22, 2009 - link

    Looking the starting times (startup and resume) I have the feeling that Ubuntu has some kind of problem on your hardware. I have quite bit experience with Dell and Lenovo and Ubuntu 9.04 is always faster to boot compare to any Windows. It is not only my experience, but I am doing test on one senior citizen and one teenager. They both agree with my observation. You should press Alt-F1 during the boot and check for any errors. Gateways could have some additional peace of hardware that does not work correctly under Ubuntu and the kernel has to wait to time-out.
    In regards out of the box experience you should get hold of the system that is optimized for Linux (Ubuntu) just like the Gateway is optimized for Windows. www.system76.com or Dell http://www.dell.com/content/topics/segtopic.aspx/u...">http://www.dell.com/content/topics/segt...s=19&... would be good start. Then you don't have to fool with drivers. I would love to see how much optimization has been done by System76 and Dell.
  • ekul - Tuesday, September 22, 2009 - link

    It's true; ubuntu 9.04 boots very quickly and 9.10 will be even better. On my netbook and my desktop 9.04 boots in a lot less then 30 seconds. I agree something isn't quite right with the boot procedure.

    The other thing to keep in mind for linux boot times is once the desktop is displayed the system is fully up. No background loading, no delayed startups. On Vista and 7 I find after the desktop appears it will take another 30-45 seconds before the HD is done reading and the system is responsive
  • oyabun - Tuesday, September 22, 2009 - link

    Thank you very much for an enlightening article. I am one of the people who indeed care for battery life!

    Regarding your testing methodology where you drain each battery over and over again, wouldn't it be more efficient to take the battery out of the equation (and physically remove it) completely? Just measure the Wh consumed by the power brick during 30 or 60 minute runs and extrapolate to the capacity of the battery. That would greatly reduce your testing times.

    You should of course measure at the DC end of the transformer, otherwise you should factor in it's efficiency.

    You could even calibrate the whole procedure with a single battery powered run. It certainly beats what you are currently subjecting yourself to! :-)

    Keep up the good work!
  • JarredWalton - Tuesday, September 22, 2009 - link

    My experience is that laptops typically switch to different power states on AC vs. DC power, even if you have all the settings the same. It's possible to estimate battery life, but I do like to do "real world" testing where possible. Anyway, it's not a bad idea and I may do a follow up article at some point looking at just the power numbers. Taking the power transformer efficiency out of the equation isn't something I'm equipped to do right now, unfortunately. I can measure power at the outlet... and that's it. And it's only accurate to ~1W there so I'd need a better device than my current Kill-A-Watt.

    BTW, have you ever stared at a small Kill-A-Watt display while running tests? Frankly, running battery tests where I can walk away and collect the results later is less painful all around! :)
  • oyabun - Wednesday, September 23, 2009 - link

    Of course a Kill-A-Watt won't cut it! You need a datalogger on a separate PC and a power gauge, logging the total energy consumption over any period of time unattended. With such a setup you would be able to measure from the DC side by splicing the wires leading from the transformer to the notebook. And, naturally, a datalogger support more than one gauge, so you could measure in parallel.

    I understand what you mean when you say that power profiles behave differently under AC. It is possible though your (and mine) experience is based on Windows XP. Perhaps Windows 7 are more consistent.
  • oyabun - Wednesday, September 23, 2009 - link

    I didn't see the comments by Kibbles before. Our posts convey the smae message!
    And I concur, the power supply testing team appears to have the tools for the job.
  • strikeback03 - Wednesday, September 23, 2009 - link

    Yeah, IIRC they're also in Europe, while Jarred is in Seattle or somewhere out west.
  • JarredWalton - Wednesday, September 23, 2009 - link

    There's more to it than that, but suffice it to say I don't have power testing equipment and it's not high on my list of priorities right now. Rough estimates are sufficient on the power side of the equation, since you get whatever power brick the laptop comes with. It's not like you can upgrade to a more efficient power brick with a Dell laptop.
  • Kibbles - Tuesday, September 22, 2009 - link

    "maybe borrow it from the powersupply setting team"

    I meant "powersupply testing team".

    Also for the convenience of being able to walk away. As long as you get a voltmeter with logging capability, you can leave it to do it's thing and just pull up the logs.

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