A couple weeks back, I posted a short article on battery life with Windows 8.1 looking at whether or not it had changed compared to Windows 8. The short summary is that no, it did not change appreciably, though at least one of the tests I ran showed worse battery life with Windows 8.1 compared to Windows 8. There are quite a few variables, and we try to minimize the impact of other elements on battery life, but since I can’t easily go back and retest the original Windows 8 results it’s difficult to say for certain if the drop is consistent among laptops or something specific to the Sony VAIO Pro 13.

One interesting subject did come up with that article, however, and it was something I wanted to investigate further. One of the readers asked about what program we were using for video playback in our “Heavy” test, and I responded we use Media Player Classic Home Cinema (MPCHC). One of the main reasons we use MPCHC is that our test video is a 1080p MKV file with a high bitrate video, specifically it’s a 10.4Mbps video stream using the AVC High L4.1 profile. The file also has a 510Kbps 6-channel DTS audio stream, and that’s where we start to run into trouble with our choice of video playback software. MPCHC supports the file natively, as does VLC, but Windows Media Player and the Windows 8 Video app would require additional codecs (they show the video but don't handle the audio). Rather than deal with those issues, I chose (back in the Windows 7 era) to simply use MPCHC 64-bit and call it a day.

Keep in mind that we’re dealing with something of a worst-case scenario in terms of battery life, so as long as the workload is consistent among tested laptops we’re don’t have a problem. However, I wanted to look at a variety of programs and decoding video on Windows 8.1, and as Windows Media Player and Video couldn’t handle our original file natively I had to resort to using a different video file.

For this testing, I grabbed a 1080p MP4 video that worked with all four video playback options. The file is a 2.03 Mbps MP4 with an AVC High L4.1 profile video stream and a 93.8 Kbps 2-channel AAC audio stream. (Update: I also used the 720p MP4 file we use for tablet battery life testing, which I only tested with the Modern Video app. It's a 4Mbps video stream using the AVC High L3.1 profile, with a 2-channel 164Kbps AAC audio stream.) I tested with MPCHC, VLC, Windows Media Player, and the Modern UI Video app – and the last I tested with and without activating desktop mode to see if that made a difference. I also tested the original MKV file with both MPCHC and VLC as a reference point.

In all cases the software is set to loop and a local file logs the time until the laptop shuts off (at 1% battery life remaining). All of the video players were using the default GPU decoding (DXVA) for the initial testing; I am in the process of running additional tests (e.g. MPCHC will be retested with EVR mode enabled). Here are the current results.

Battery Life - 1080p Video Playback

The results are interesting to say the least. If we start with the MKV file compared to the MP4 file, VLC actually ends up doing a bit better than MPCHC by 7%. Switch to the lower bitrate MP4 file and MPCHC comes out ahead by 3%. There are differences, but it’s not so much that one would worry much about it. It’s when we start to look at the two Microsoft applications that we get some startling results.

Windows Media Player manages 418 minutes of playback time with the MP4 file – or 32% better than MPCHC and 36% better than VLC. That’s a huge difference and suggests that Microsoft still knows a thing or two about optimizing better than the third part video applications. If that’s not enough, the Windows 8 Video app ends up surpassing Windows Media Player by an additional 13% in Modern mode – or nearly 50% more than MPCHC and 54% more than VLC.

As for launching from the desktop vs. staying in the Modern UI, we see a 2% difference by staying within the Modern UI, so it’s measurable but not massive. Personally, I use so many desktop mode applications that I'm not sure it's realistic to even stay exclusively in the Modern UI, but it does make a slight difference in battery life.

Of course there’s more to the story than simply which media player gets the best battery life. Are they all showing the same quality and doing the same work? That’s difficult to say without further analysis. It could be that WMP and Video are offloading more work to the GPU than CPU, or perhaps the opposite. Either way, the battery life results show just how big of a factor software optimizations can be.

Looking at the big picture, with the Windows 8 Modern Video app and sporting a 37Wh battery, the Sony VAIO Pro 13 manages nearly eight hours of battery life on a 1080p video file. Our tablet video file is a 720p video file with a higher bitrate but lower resolution, and with that Surface Pro 2 and updated firmware gets just under eight hours of battery life as well – on a smaller 10.6” display and with a higher capacity 42Wh battery. (Note that Anand tested Surface Pro 2 with the Modern Video app as well.) Update: I tested the VAIO Pro 13 in the Modern Video app with the 720p tablet MP4; battery life is slightly higher than with the 1080p MP4, as seen in the updated chart.

It’s clear that Sony has done more to optimize for battery life on the VAIO Pro 13 than any other Haswell laptop that we’ve encountered. We’re still not at the point where Haswell with Windows 8 matches the various Android or iOS devices on video playback, but with the right tuning of hardware and software that goal may be within reach, especially with a 10” display and other hardware tweaks. Unfortunately, most laptop manufacturers haven’t put in the effort to get there, but Sony shows what’s possible and we hope to see better efforts in this area from other manufacturers going forward.

I'm still looking at running additional tests of video playback battery life on the VAIO Pro 13, while I still have it in hand. If you have any specific requests (e.g. "Run MPC-HC version XYZ with the ABC decoder"), send me an email and I will try to accommodate any reasonable requests. Keep in mind that every test run requires at least six hours (including recharge time) and as much as ten hours, so realistically I can at best run two battery tests per day. Again, feel free to email me if you have any other suggestions or questions.

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  • JarredWalton - Thursday, November 7, 2013 - link

    Keep in mind that the "Heavy" test is designed more as a worst-case scenario and the use of MPCHC on Windows platforms means all of the tested laptops are on equal footing. Comparing Windows with OS X of course creates complications -- and that goes for the choice of audio playback software in the Medium test, web browser selection, media player, and other power settings. Apple does very well at optimizing their OS and software for battery life it seems, but I've always been a bit hesitant to compare cross-OS battery life scores for the above reasons. Reply
  • michael2k - Thursday, November 7, 2013 - link

    If we're going to suggest cross platform software, I would suggest iTunes+QuickTime. The problem is Apple won't optimize for Windows, so the next best solution would be to use MP4+AAC and use iTunes on Mac and WMP on Windows. Reply
  • rainking430 - Wednesday, November 6, 2013 - link

    To play files with DTS audio streams as well as MKVs in the native apps, I use Shark007 codecs which, unlike other codec packs, keeps the install/uninstall and setting changes very clean (just beware the offers to install malware when you first install the pack, sigh). Changing to Gabest splitter under the MKV and MPG~MP4 tabs will do the trick. Reply
  • bountygiver - Wednesday, November 6, 2013 - link

    Love that codec, no bloat and useless stuffs, clean all-in-one shortcut to settings and good integration with all existing players. Highly recommended. Reply
  • JNo - Thursday, November 7, 2013 - link

    Does Shark007 install easily alongside existing installed codecs/players? (I have K-lite codec pack & VLC).

    Or will it interfere with them and I should uninstall those first?
    Reply
  • rainking430 - Thursday, November 7, 2013 - link

    You need to uninstall those first. Not 100% certain, but I think the installer detects other packs and will automatically uninstall them for you with your permission. Don't quote me on that though as I've never had to do that myself.

    Also, please remember that it will try to trick you into installing malware the first time you install it! So be vigilant! Why Shark007, WHY????

    FWIW, I also set everything to use ffdshow dxva codecs, I find I get the best experience with that combined with my settings I posted before.
    Reply
  • jhoff80 - Wednesday, November 6, 2013 - link

    Personally, I kind of wonder how a Metro MKV player like mobile.HD would compare to the desktop apps. Reply
  • teiglin - Wednesday, November 6, 2013 - link

    I'm curious if there's any way to determine exactly how much of the decoding is being offloaded to the fixed-function logic blocks on the CPU rather than by software--I almost never play longer videos on my laptop off of airplaines, and my kids are at an age where having my laptop open and watching a movie in flight is challenging, so that is also largely a moot point for me. However, I'm interested in a comparison of the video decoding logic in Haswell and the logic in my various ARM SoCs (and Bay Trail too!); any thoughts you have would be greatly appreciated.

    If you do feel like adding one more test, YouTube is probably the most-used video player on my laptop, though doing a proper comparison with YouTube probably requires uploading a video, then downloading the video that gets posted, as I have no idea what sort of software Google is using on their end to do the encoding. And I have no idea if it's possible to get YouTube to cache an entire video and play it forever, so maybe it's hopeless to get a real comparison--but even a non-comparable data point would be good to see.
    Reply
  • skiboysteve - Wednesday, November 6, 2013 - link

    Jared you are awesome. Thanks for listening and spending the time to test. this data is great! Reply
  • skiboysteve - Wednesday, November 6, 2013 - link

    Jarred* Reply

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