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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  • nortexoid - Wednesday, September 23, 2009 - link

    I'd like to see a test done using "regular" office apps (openoffice, acrobat reader, etc.) and NO internet browsing. (Yes, that's how I use my computer off the plug usually.) It would weed out the performance usage hit taken by Ubuntu when flash is running.

    It might also be interesting to do a test with tweaked systems, e.g. by tuning Jaunty with PowerTop or similar apps. How does each OS perform when FULLY optimized for battery life (without sacrificing features or much performance, of course)?
    Reply
  • 7Enigma - Wednesday, September 23, 2009 - link

    I know there are users (Jarred apparently you are one of them) that run a system without antivirus/spyware, but you are (or at least should be) in the minority. Linux distro's apparently can get away without it, but on ANY Windows box it's a MUST HAVE. Also disabling those other services (while good at reducing variables) again undermines the system's protection and comparisons to a general usage scenario.

    In your article I do not think you mentioned what you tweaked (but I could have overlooked this). From my initial impression when reading the article you took both OS' as they were default installed and then tested from there. I think you skewed the results badly in the favor of the Windows platforms by doing this, and I say this as a Windows-only user (never used Linux in any flavor). The first thing I do after a fresh install (still on Vista) is turn off all of those programs you did, along with a host of other services/eye candy using BlackViper's Vista Tweaks. This significantly speeds up the OS in all aspects but can hardly be considered most users configs.

    At first reading these comments I was firmly on the "sour grapes" to all of the Linux users complaining about what distro was used, or why X wasn't tweaked by going to a website and reading a tech article, but now I kind of agree with them. Your experience with Windows and lack of experience with Ubuntu had you setting up one for failure before the first test was even run.

    Either you test both OS' as they are default installed (driver incompatibilities aside), or you need to have a Linux semi-guru set up your Ubuntu box. My recommendation is the former, as the latter has so many variables it's probably not worth testing in the first place.

    Aside from the Ubuntu portion I enjoyed the article. It was very interesting to see how the different power profiles jockeyed for position. I would like to second an earlier commment that asked for idle time to shutdown numbers. Let's be honest, most of us are not going to surf continuously from 100% to dead battery. Rather we are more likely to use the laptop for a bit and then walk away, and come back later. It also will give a good indication of those background tasks impact on battery life (if you don't disable them in your config). I have a sneaky suspicion XP might look very good as it seems to be quite a bit more bare-bones than Vista/7.

    Thanks again.
    Reply
  • code65536 - Tuesday, September 22, 2009 - link

    An Intel engineer explained it some years ago in a blog posting: XP's max battery basically throttles the CPU's frequency down all the time. For example, on my Core2Duo, it'd mean that the CPU will operate at 800MHz all the time, even when it's busy. On the other hand, if Windows gives Speed Step a free hand and lets Speed Step determine the speed, then the CPU will operate at 2GHz when busy, and slow to 800MHz only when it's idling. According to this Intel engineer, it makes no sense to have it always throttled to 800MHz, because that means that tasks will take longer to finish, and the CPU will spend less time idling (which is when the CPU *really* saves power), and he labeled the max battery mode as the "what the hell are you doing?" mode. Reply
  • Drizzt321 - Tuesday, September 22, 2009 - link

    I completely understand your complaints on the length of time required to run the test, plus recharge the battery. Have you considered buying a 2nd or 3rd battery and finding an external charger? Or would that kill the results of the test because the battery would be different? Reply
  • PepperPot2 - Tuesday, September 22, 2009 - link

    I fail to believe you included the default grub time in the boot as this to do so would be unrepresentative of real use. Who would sit there and wait for it to time out rather than just press the enter key triggering the boot process? Anyway a default install of ubuntu (where it is the only OS on the machine) doesn't show the grub menu, only a 2 second alert to allow you to bring it up if you want. I then immediately boots.

    My experience with ubuntu is totally contrary to the conclusions you just posted about speed. We've have ~20 installs of Ubuntu 9.04 at work on old machines (7 yrs old) to a machine I built 1 month ago. In all instances the staff find it it is smoother and quicker to use than the dual boot copy of vista or XP.

    The boot time on XP is clear nonsense, when ubuntu boots to the desktop you can use it almost immediately. XP is typically totally unusable for ~30 seconds while it loads more crap in the background. Vista is worse.

    Reply
  • jasperjones - Tuesday, September 22, 2009 - link

    That's true, XP and Vista are pretty unresponsive for a minute or so after boot on your average entry-level laptop. OTOH, Ubuntu is snappy once you see the GNOME desktop. 9.04 is called jaunty ducy ;)

    However, the same can be said of Win 7. It keeps loading stuff after you see the desktop, but that doesn't make the system feel sluggish--not at all
    Reply
  • JarredWalton - Tuesday, September 22, 2009 - link

    The Windows boot times are stopped when I see the default system try icons appear (WiFi connectivity, volume, etc.) so the system is pretty much usable at that point. As for GRUB, it's a 2 second timeout, which I could bypass by pressing enter twice, but that still leaves around 8 seconds from the POST to the point where it looks like Ubuntu is actually loading. What's going on during that time? If we subtract POST times, then Ubuntu would look even worse. I can see about tweaking GRUB to skip straight to loading the OS and see if that helps as well... when I get time. Reply
  • jasperjones - Tuesday, September 22, 2009 - link

    FYI--one can simply configure GRUB to not wait for user input by editing /boot/grub/menu.lst and changing the second or third line from "timeout x" to "timeout 0"

    But I generally completely understand the argument not to change too many things from the default installation of Ubuntu, as it's doubtful that the average user would do it.
    Reply
  • maveric7911 - Tuesday, September 22, 2009 - link

    I would love to see a properly installed and setup distribution of linux in this review (not bashing love that you included linux at all). As others stated above Archlinux would be a pretty good choice. All packages come optimized and things like native 64bit flash and other native 64 bit applications are apart of the stable repository "no adding repos necessary". Also as mentioned, not using the hardware accelerated driver of ati or nvidia will take a big hit on power right away. I'm always available to assist with any linux testing and/or questions.

    HP
    Sr Linux Engineer
    Reply
  • andrewaggb - Tuesday, September 22, 2009 - link

    What I would like to see is Jared run all the tests on his version of Ubuntu, then let a linux expert have some ssh love to tweak it all up, and then let Jared run the tests again and see how much difference he finds. Reply

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