OS Mobility Explored

Conclusion: Round 3?

After looking at the initial Internet battery life results from both tests, one thing is abundantly clear: using live websites with variable content isn't the best way of doing things. One of our original test websites appears to have become less strenuous during the past month or so (perhaps one less Flash ad is showing), and there's always a risk of radically different results if/when a site undergoes a redesign. As much as it pains us to say this, we have to consider all our Internet battery life results suspect at this point. Worst-case, they may be off by as much as 10%.

Going forward, we are working to create some test webpages where the content will be strictly controlled - i.e., identical between test runs. We expect there will always be some slight variation between test runs, but the present variation of up to 10% in some cases is far too high. We could run each test half a dozen times and take the median result, or throw out the high and low scores and average the remaining results. However, running even two tests on each laptop for each test configuration can rapidly result in several weeks of testing and we certainly don't want to triple the number repetitions for each test when they can take several hours to complete.

At any rate, we have started testing with a third set of websites, and hopefully the results will remain consistent for all OSes - and web browsers. We should probably mention that the results in those browser battery life tests are also suspect at this point. We completed those tests several weeks ago, and at the time the results between test runs appeared to be relatively consistent, but we're no longer even 90% confident in those results. We will follow up once we have confirmed our latest testing procedure. Our plan is to start with Windows Vista, perform several test runs on each laptop, confirm that the results are consistent - i.e. no more than 2-3% variation between test runs for a given power profile - and then retest the other operating systems. Once we have tested Windows XP, Win7, and Ubuntu we will reinstall Vista and repeat the tests one last time to confirm that there has been no variation over the course of a couple weeks of testing (or however long it takes). Then we'll think about looking at more browser battery life tests.

Unlike the Internet battery life results, we can discuss DVD battery life results with relative confidence. We use the same DVD, and variations between test runs have always been consistent. We plug in a set of headphones and use Windows Media Player for the DVD playback test. Windows 7 was clearly the winner in this particular test on the Gateway NV52, beating Windows XP by around 6% and Windows Vista by 22%. Again, however, changing to a different platform muddies the waters. On the Gateway NV58, Windows Vista is clearly in last place; XP offers about 21% more battery life and Win7 offers 18% better battery life. That said, this time Windows XP beats Windows 7 by around 3%.

We also said that we weren't going to focus on AMD versus Intel, since we've already looked at that aspect of battery life on these laptops. However, there's no getting away from the fact that the Intel platform offers substantially more battery life. Over 30% more time for each battery test means we only get three or four runs per day compared to four to six runs. (Note that it takes another 90 minutes or so between tests to recharge the battery, and we're not always around to immediately plug the laptops in at the completion of a test.) That means it takes the NV58 anywhere from 4.5 to 6 hours per test compared to 3.5 to 5 hours for the NV52 - and we do need to sleep at some point.

The average increase in battery life over all of the tests we performed so far is 33%, and that's taking into account the fact that Ubuntu closes the gap quite a bit between the two platforms. Throw out that Ubuntu result (only 13% in Intel's favor) and the average battery life lead increases to 37%. Why should we throw out Ubuntu? If you took the time to read this article, you already know that Ubuntu is consistently the worst battery life of the tested operating systems. As much as people like to complain about Windows, manufactures have worked a lot more on optimizing battery life performance for Microsoft's OSes. Then again, as we repeatedly mention in laptop reviews, Apple's OS X is in a league of its own when it comes to battery life. Not surprisingly, having full control over your operating system and hardware can give you a real advantage when it comes to laptop mobility.

The final topic to address is OS performance. Again, we have to pretty much throw Ubuntu out of the running. These are by no means high-performance laptops, but surfing the Internet using Firefox on Ubuntu makes you think you're running an Intel Atom netbook instead of an entry-level notebook. By no means are we discounting Linux in general, and it's still very difficult to beat the price (free); however, we think the vast majority of users will be more than happy to pay the cost for a Windows operating system. Looking at performance on the Windows OSes, once again there are some interesting trends to note. In PCMark05, Windows XP consistently scores higher in every individual test than Vista and Win7; the exception to this statement is the 2D Transparency test, which makes it look like Windows XP is old and outdated. Generally speaking, Windows XP just feels a little snappier than Vista on these laptops, probably due in part to the fact that it has a smaller memory footprint. On the other hand, Windows 7 is the clear victor in general system performance. We would love to have PCMark Vantage results from Windows XP, but unfortunately that's not going to happen. As it stands, Windows 7 outperformed Windows Vista by 15-20% in PCMark Vantage; the individual multitasking test results in PCMark05 also favor Windows 7 over Vista by an average of around 5%.

Without running a reasonable number of game benchmarks, we are not prepared to make any statements about the 3D graphics performance of any of the Windows operating systems. The various 3DMark tests show little to no difference on the NV52, but the NV58 shows differences of 3-19% in the earlier versions and a whopping 84% difference between Vista and Win7. Considering that these notebooks are anything but fast when it comes to gaming performance - IGPs still don't perform very well compared to discrete solutions - and the variations we see may simply come down to driver optimizations. We will leave any firm conclusions about differences in overall Windows performance among the various OSes to the desktop people for the time being. As a laptop OS, we would definitely take Win7 over Vista, but despite UI improvements we still find Windows XP to be more than adequate for most users. Secure? No, but still adequate if you know what you're doing. :-)

At this point, you're probably wanting more information, and admittedly we've only scratched the surface. How do other browsers fare on other operating systems? What about a better Linux distro than Ubuntu? What happens if we use FlashBlock - or a similar add-on - with these other browsers? Can we improve battery life by using a different media player or codec? What about Mac OS X, including differences between Snow Leopard and Leopard - and Tiger, Panther, and maybe even Jaguar if we want to go nuts? Give us time, because if there's one thing we know for sure it's that conducting battery life tests can take a while to complete.

To Be Continued….