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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Kibbles - Tuesday, September 22, 2009 - link
If all you have is a killawhat meter then that'll be pretty inaccurate. Not just because of the 1W accuracy but also measuing at the outlet you are also including the inefficiency of the powersupply.However I do agree that using the battery is throwing an extra variable into your equation. How big is it? I don't know. But I do know they don't always charge to the same capacity, and their capacity changes overtime.
I don't know if it's possible, but I would think the best option would be to have a DC source modded into the battery connection. Then measure the #W-h used. You would probably need a good variable DC supply and voltmeter to do this (maybe borrow it from the powersupply setting team?). Even then I don't know if you can do that, I think my laptop has like 6 pins on the battery. There's probably some connection for charging, some for battery status, and then the discharge connections.
The second option I see is putting a voltmeter on the DC-out side of the powersupply going into the laptop. You could run the benchmark without the battery for an equivalent duration and see if the W-h is close.
n0nsense - Tuesday, September 22, 2009 - link
Power savings in Ubuntu are far from optimal.I was more than surprised to see that even very basic features may or may not work.
For example on my Gentoo box each core frequency scaled separately.
On Ubuntu some processors are not supported. After all I thought that engineers at Canonical have better kernel understanding than me.
As for the tests, dim option is helping with battery life.
I don't remember such difference in battery life from my experience. Both Linux and windows where capable of ~3Hr on my laptop.
From my very personal point of view, Ubuntu is sluggish. I compared Ubuntu, XP, 7, Debian and Gentoo performance on IBM X31 with 1GB ram.
It started without Gentoo (It takes a while to setup fully optimized Gentoo box). Ubuntu and 7 where (IMHO only)the slowest. Debian and XP where just fine. But since I wanted more, i did the Gentoo thing. It was more than worth it.
With Ubuntu it was overall sluggish feeling (some tests will show much better performance under it than in windows). But feeling is important when you use something. Even more important than some numbers.
7 ... Same sluggish Vista with facelift and few tweaks that can be manually done.
Watching icons drawn few seconds after menu displayed was more than enough. It is more stable, can work longer without reboots, but nowhere faster than XP.
Debian with Gnome was nice so was XP. Anyway I'd stay with Linux since it's more customizable and have few useful things that make me feel handicapped in Windows.
Gentoo once again convinced me that it worth each second (it took more than 2 days on X31. should be much faster on any dual/quad core CPU and/or using distcc). But, not everyone can do it. Even "experienced" Ubuntu/Fedora/Suse (or whatever mainstream distro) may find that his understanding of "how staff works" is not on the required level.
Anyway it's quiet a change to see Linux participating in review.
Good job guys :)
lordmetroid - Tuesday, September 22, 2009 - link
I'll be running Arch Linux on my nettop, I tried gentoo 4 years ago from stage 1 and that was a nightmare to get installed. Maybe I should try it again but Arch Linux seems to be more interesting at this point as it had many of the packages I want in its repositories that I couldn't find in gentoo.stmok - Tuesday, September 22, 2009 - link
Running Arch Linux here on my ThinkPad T43...Much better than Ubuntu.Ubuntu feels bloated. Heck, even Xubuntu feels bloated.
void2 - Tuesday, September 22, 2009 - link
30..40 seconds to boot WinXP on modern CPU? That's sad. I get 7..8 seconds (boot menu to desktop, add your machine POST time yourself) on a comparable CPU (Athlon 64 X2 3800+). Clean OS, no SSD, no messing around with disabling services etc. How? Use Boot Cooler (www.bootcooler.com). It is free.lyeoh - Tuesday, September 22, 2009 - link
Why should anyone use bootcooler? The website doesn't even say what the program is _supposed_ to do, and how it achieves it. I don't see much on the web that describes or tests what it _actually_ does (as opposed to just claims), the limitations etc.It could be a trojan for all we know.
void2 - Tuesday, September 22, 2009 - link
If you haven't noticed, the website is under construction. Detailed explanation of how Boot Cooler works is included in readme.txt (in short - disk reads prefetching). And of course there are no reviews yet - the project is still in beta.orionmgomg - Tuesday, September 22, 2009 - link
I love antech - waiting for the radeon hd 5870 info to hit - looking at this artical - something about your battery lasting longer on your lap top...WHO CARES!!!
Give me a brake - you spend so much time on analizing minutes of extra juice it a fly is in the room or not! WHO CARES?
Plug your lap top in the wall - dont expect it to last any longer than it does when you have a full charge and it runs out of juice.
Once you know how long it lasts - realize your screwed - or should I say attached to the power cord!
Oh - did I mention - who cares?
Thanks for all your other articals!
orionmgomg - Tuesday, September 22, 2009 - link
I love Anandtech*^JarredWalton - Tuesday, September 22, 2009 - link
If you haven't figured it out, I'm the mobile reviewer at AnandTech, and my articles are about mobility. Writing articles about laptops doesn't mean I'm delaying any CPU or GPU reviews -- unless they happen to be mobile CPUs/GPUs. If you don't care about laptops, you don't need to read most of my articles, but please don't make the mistake of assuming no one cares. When people use a laptop on the road and don't have a chance to plug in, articles like this are very useful. If you never use a laptop, great; some people do and that's my target audience.