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.
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?
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JarredWalton - Tuesday, September 22, 2009 - link
What I would love is to have a definitive Linux source that I can use that will "just work". But that's probably asking too much. I've now got suggestions to try the Ubuntu Netbook Remix, Moblin on the NV58, and Archlinux.And hey, if anyone lives near Olympia, WA and wants to come give the Linux install some fine luvin' let me know. LOL
stmok - Wednesday, September 23, 2009 - link
quote('What I would love is to have a definitive Linux source that I can use that will "just work".')That isn't going to happen. Simply because Linux isn't Windows or OSX. They approach things with different paradigms.
Per Hansson - Tuesday, September 22, 2009 - link
Hi, something I have noted when installing AMD laptops with a clean RTM WinXP disc and not the bundled one that includes all drivers + lotsa more crap you don't want;In all cases the systems have not been throttling the CPU speed or CPU voltage, I have had to install the AMD PowerNow! driver and then everything has worked (even though both AMD and Microsoft say this is included with XP!)
The difficult part is actually finding the driver, since both AMD and MS feels it is not needed it can be a real pita, please verify with CPU-Z or similar if your systems have this issue
JarredWalton - Tuesday, September 22, 2009 - link
Vista definitely worked properly - I saw CPU speeds of down to 1050MHz (5.25 x 200) on the NV52. Since XP and Win7 both achieve similar results, I think it's working right but would have to check. I'll try to be more careful for the next tests. :)jasperjones - Tuesday, September 22, 2009 - link
I assume you ran Ubuntu with the 32-bit Flash plugin (that's available on x86-64 via nspluginwrapper (Netscape plugin wrapper).I'd be curious to see how results are with the native x86-64 Flash which is available as an alpha on Adobe Labs.
For the last two or three years, I've had nothing but problems with 32-bit Flash on a 64-bit OS and those problems finally somewhat subsided after moving to the 64-bit native alpha build.
clavko - Tuesday, September 22, 2009 - link
Actually, graphics card power management with open source ati drivers (xf86-video-radeon and xf86-video-radeonhd alike) is not up to par with custom power management of fglrx proprietary driver. If tests were made using open source drivers, some of the battery time difference should account for that.However, I find it quite fair comparing Windows to Ubuntu, given that Ubuntu really is considered vanilla, desktop user distro. Obviously, things are not exactly "there" yet, but I'd be interested in power consumption with newer fglrx drivers, perhaps on OpenSUSE.
strikeback03 - Tuesday, September 22, 2009 - link
On my laptop (T40, 1.86GHz Pentium M Sonoma) I primarily use Ubuntu, with XP when I need Photoshop or Lightroom. I never measured the battery life exactly, but never felt it was that different, certainly not by a third. Do you have the scripts to run the internet test I could try and see what my results are?I also never felt Firefox was notably different between XP and Ubuntu, both misbehave in different ways. The notable exception is flash in 64bit Ubuntu on my desktop, which is of course more hit-or-miss.
JarredWalton - Tuesday, September 22, 2009 - link
Send me an email.gwolfman - Tuesday, September 22, 2009 - link
When I originally purchased my Dell Mini 9, it shipped with Ubuntu. Rather than coming with the standard/original kernel, it came with the Low Power Intel Architecture (LPIA) kernel. I'm not sure what optimizations are done with regards to the kernel, but do you think it's worth looking into with regards to the bad numbers you got from the default kernel bundled with your Ubuntu install? Maybe there are some optimizations for battery life in there that are not included in the standard kernel.vol7ron - Tuesday, September 22, 2009 - link
As nice as these tests are, I think the reliability/consistency may be overlooked a little bit. I'm not saying it's not reliable/consistent enough, you've already touched on that in the final paragraph, with regards to the websites themselves. What I'm saying is that there are other factors that may be affecting battery life.Are you using a multimeter to measure the power consumption, or are you just letting the battery drain and measuring time? I'm guessing that if you just let your computer start up and run it's battery drain naturally (no erroneous applications running), the battery life would also vary in minutes.
I also am assuming that these devices aren't cooled to the same temperature, before tests begin. Heat not only dissipates the energy stored in the battery, but it also requires more power to the fans for cooling. As I've touched on in another article, processor speeds vary - that's something that is truly hard to keep consistent, since it is irrelevant to BIOS settings. It'd be interesting to see if a processor running at 2.096 vs one running at 2.104 over an extended period of time has enough impact on battery life.
That being said, it's also known that processors vary in clock speed even after it's started, so I'm not sure if any points I've made can be applied in setting a realistic control at this point.
My last point is about the battery itself. Manufacturers claim the battery is "good for" a certain period of time, but these batteries are often "cheap" in quality. I think a few uses could impact the natural battery life; this goes back into testing regular start-up/shut-downs, w/o running any tests.