9860 and 7620 DVD playback on battery

[andrepeterhill]

I've posted this information in another thread as a response but thought it deserved a post and discussion of its own. The following is my finding regarding DVD playback on battery with the 9860, not something that most of us care about due to it's limited battery life - but it relates to the possible/probable performance of the upcoming 7620 which is based upon the same/similar architecture but has the benefit of lower power consumption and an optional second battery, giving it up to almost 2hrs of battery life as revealed in Adam's review.

I have a highly optimised 9860 (bare minimum background tasks and services - with 2GB of installed memory my startup pagefile usage is less than 200Mb) and I've done extensive testing with PowerDVD 6, WinDVD 5, Windows Media Player 10 and Nero ShowTime 1.5 and they all exhibit the same symptom, the following is an example of my findings after numerous tests.

I start my fully-charged 9860 on battery power with the screen at it's lowest backlight setting, once I've started playing the DVD I turn the backlight up to the 2nd highest setting (this conserves a little battery power but is still nice and bright with high contrast and good blacks), I also run the DVD at full-screen (all movies I've tested are widescreen 16:9/2.35:1 with letterbox).

In this optimal scenario - 22mins after I turned on my 9860 to play my DVD the battery power has run down to 58% at which time (no matter what player I'm using or which drive I'm using - including DMA enabled drive/s) the DVD begins to run jerkily, this may not appear obvious to everyone but it is definitely skipping frames quite noticeably. Up until the battery gets down to 58% DVD playback is perfectly smooth but after this it takes an instantly noticeable performance hit.

From here, if I'm using WinDVD the movie will play jerkily for a further 21 minutes before the battery power reaches just 14% and WinDVD stops playing. PowerDVD will continue to play the DVD (once again jerkily) beyond the battery dropping to 14% for a further 5 minutes at which time the system alarm alerts me that the battery is at 6% and I need to shutdown, I shutdown as the battery reaches 5% having achieved just 49 minutes of up-time from the moment I first turned on the laptop.

If I disabled the system alert at 6% battery remaining and just ran the laptop till the battery was dead (which wouldn't be too good for Windows) I could probably leech a few more minutes but that's about all.

So basically, all I get out of my 9860 is 20 minutes of smooth DVD playback before the battery hits 58% and the playback becomes jerky, if the 7620 can achieve double this performance because of it having twice the battery life that still gives it no more than 40-45 minutes of "acceptable" DVD playback.

I admit that what I term "acceptable" (no noticeable skipped frames) may not be the same for everyone and other users may be happy with DVD playback that skips a few frames every 5 seconds, but I suspect that there are plenty of users who like me would deem this unacceptable.

[ls3mach]

You didnt take into account that the 7620 has a smaller screen. This will automatically use less power.

[andrepeterhill]

Originally Posted by ls3mach

You didnt take into account that the 7620 has a smaller screen. This will automatically use less power.

Yes I said that the 7620 has less power consumption, the smaller screen is a big part of that as is the fact that with the extra battery installed it has only one hard drive, one optical drive and no 7-in-1 card reader - these are what give it around twice the battery life of the 9860 with only one and a half times the battery power (according to PCTorque it takes a standard 6600mAh battery plus a half sized 3300mAh battery in the media bay). I allowed for this in my comments above, hypothesising that it would run smoothly for twice as long as the 9860 (maybe even a bit longer) - still only giving it 45mins of smooth playback at most though.

[Luke@NBF]

So far in all of my tests with my 9860 I have been unable to relate battery consumption to choppy video. I did my run of a video with Outlook 2003 and a web browser running, I also have my desktop extended on to a second monitor... none the less more power consumption on the battery. While both the programs I was running were idle I had no drop in FPS on my movie. While trying to browse the web or query our exchange server I would see noticeable skipping and as soon as those applications would idle again my FPS would turn to normal. So thus far I have been unable to reproduce the issue that you are having. This is running Power DVD w/ my settings at always on for power, as to not interrupt testing when the notebook is idle. All my video setting are at stock and this is with a fresh OS install.

[andrepeterhill]

Originally Posted by Luke@PCTorque

So far in all of my tests with my 9860 I have been unable to relate battery consumption to choppy video. I did my run of a video with Outlook 2003 and a web browser running, I also have my desktop extended on to a second monitor... none the less more power consumption on the battery. While both the programs I was running were idle I had no drop in FPS on my movie. While trying to browse the web or query our exchange server I would see noticeable skipping and as soon as those applications would idle again my FPS would turn to normal. So thus far I have been unable to reproduce the issue that you are having. This is running Power DVD w/ my settings at always on for power, as to not interrupt testing when the notebook is idle. All my video setting are at stock and this is with a fresh OS install.

After your response here Luke (and Adam's in another thread) I've gone back and done some more investigation, I found that if I enable Video Hardware Acceleration in PowerDVD (which isn't enabled by default) it now runs smoothly even near the end of the battery life (turn it off and it goes back to being jerky). Video hardware acceleration is greyed out (not available) in WinDVD, Nero ShowTime doesn't appear to have it as an option and Windows Media Player 10 actually isn't all that bad even without specifically enabling this feature (it just has bad colour reproduction and doesn't really play full-screen).

So it appears that as long as users are running PowerDVD with Video Hardware Acceleration enabled they should be fine. This is good news for potential 7620 buyers who can expect almost 2hrs of smooth playback with this feature as long as they're running PowerDVD.

[Flats]

AndrePeterHill, thanks for posting your note. I have the same problem on battery power and noticed the same jerky behavior once the battery hits 60%. It is so annoying I turn the computer off. I have PowerDVD6 and will try to enable hardware acceleration to see if that helps. Great post!

[Rustican]

I don't think the jerkey behavior is good. It sounds like the battery is surging or sputtering, unable to push a constant voltage through the system once the power level reachs a certain point. This is bad for system longevity and could cause components to prematuraly burn out. Luke, what's your oppnion on this? Is there some responce from Sager?