DRM and battery life: no real effect after all?

Last month we wrote about a CNET study that quietly laid claim to PlaysForSure DRM cutting player battery life by as much as 25%, and FairPlay draining iPod batteries by up to 8%. DAPreview put it to the test, though, by comparing playback time on 25 albums in 160KBps non-DRMed and DRMed WMA in sequence on a fully charged SanDisk Sansa e260 with volume at 50%, screen brightness at low, and the backlight left on. And wouldn't you know it, the DRMed files played all of 25 minutes less, or 2.8% less than the 14:55 pulled from the non-DRMed music. However, since the test was only run on a single device, this only means you can conclude that the Sansa e260 handles DRM well; with so many chipset designs for player internals, you couldn't expect all devices to produce the same positive results. But hey, it's encouraging, if nothing else -- especially if you're a Sansa e260 user.

[theattack @ Apr 10th 2006 12:55PM]

are there Sansa E260 users yet? I thought these weren't released yet? and if so where can i get one?

[JShenkens @ Apr 10th 2006 12:58PM]

Sorry, this is far from definitive. One sample per variable? Come on! You would need at least 10 tests per variable to get any kind of useful information. You obviously never took statistics before.

Plus your rechargeable li-ion battery is a huge variable and inconsistency across tests. After only one test of the battery it is not in the same state and cannot be used for to test a different variable. If you wanted to test a player with a rechargeable battery you need to have one brand new player per variable, in this case 2.

[nick @ Apr 10th 2006 1:03PM]

"and the backlight left on." that right there tells you that this test is BS. the screen back light has got to take up MASSIVE ammounts of power in comparison to the processing.

[JinKazama @ Apr 10th 2006 1:08PM]

C'mon engadget. You know good and well that this "study" holds water about as well as a paper bucket.

Like the guy said above one sample? At least Cnet's study while not iron clad had a little more validity.

What this does show is that DRM'd music has an effect on battery life. Sure glad I still buy CD's and just burn them to my player. Maybe that's why I couldn't figure out what all the fuss was about over the ipods battery life.

[John Lane @ Apr 10th 2006 1:14PM]

The testing method is highly unscientific and inconclusive. The player should be measured to see how many MiliAmps it draws while a non-drm file and a drm-file, batteries change, you can't get a perfect charge each time. As well as the backlight should not be on continualy, as that is not standard use, and further skews the test.

This "test" was simply propaganda showing how easily tests can be skewed, and how lacking most sites testing capabilities are.

[x23 @ Apr 10th 2006 1:17PM]

"At least Cnet's study while not iron clad had a little more validity."

the CNET study was comparing apples and oranges. not just a bit short of iron clad but not even in the same country as iron clad.

[Bill @ Apr 10th 2006 1:28PM]

It doesn't matter that the backlight was on, since it was on for both the DRM and not DRM files.

[Moogle @ Apr 10th 2006 2:08PM]

DAPreview's own description of the typical battery life is over 20 hours, and his tests showed 14.5 with the backlight on. So the backlight causes the unit to use about an additional third more power. So that 2.8% is of the larger power usage, so it's a bit higher percentage of the normal usage ammount, so off the bat, probably 5%.

Then, take into account that the higher battery drain will skew the discharge rate. It's impossible to say how much without extensive testing, but it's conceivable that it could affect it as much as the 8% reported for the iPod.

So no Bill, I'd say the backlight being on was pretty important.

And this is ignoring whether the device itself performs efficiently on non-drm files since it has a processor capable of handling drm that might be fully powered. If the DRM support weren't there at all, there could be a sizable power saving.

[thispaceforsale @ Apr 10th 2006 3:23PM]

Another issue to think about is being forced to use WMA. As there is no DRM'd mp3, right? So DRM, even though it may not decrease battery life, brings with it baggage- the requirement to use a format that does decrease battery life.

[Eli @ Apr 10th 2006 4:30PM]

I can't imagine that DRM you could affect battery life. You'd think it would just do some DRM check when it starts playing a song not continuously. Seems like complete FUD.

[schmic @ Apr 10th 2006 5:10PM]

why ten? Where does this number come from? You don't have a clue how much the numbers vary and you want to tell how many tet runs you need? You need to agree a p value and test until you reached that one! My guess is that you'll never reach a sensible p value with this set up. I agree that voltage and amperes should be measured. Then as stated before, you'll have to do it with your own device, since it will be chip dependent! And backlight defenetly plays a role (as allready explained)... this experiment was not properly designed!

[Will @ Apr 10th 2006 6:19PM]

CNET compared DRM'ed WMA and AAC against MP3, so that test was pretty useless as it's well known that those audio codecs are more hardware hungry than good old MP3. The DRM thingy is done in hardware, so it can't be too power drawingly.

[Mike C. @ Apr 10th 2006 9:45PM]

This is not Scientific America, people, lighten up. Engadget does not claim this simple test shows anything conclusive. They claim little other than the results might be good news for owners of the same mp3 player. What, no one can share results of a simple test like this with others on the internet now? You only want to hear about test that took place in a lab on 100 idential units run by engineers? Come on, they just performed a little "out of curiosity" test and shared the info. Most readers should be able to understand this and take the results with a grain of salt.

[fondy44 @ Apr 11th 2006 12:46AM]

"At least Cnet's study while not iron clad had a little more validity."
How so? They didn't even bother to use the same codec in their study.
I believe the whole point of the DAPreview test was to point out that the Cnet tester wouldn't have seen such a big difference in battery life, had he used the same codec for the unprotected file that he used for the DRM'ed file. Instead, the Cnet guy compared WMA DRM to MP3, which is about as fair as running a fuel economy comparison between a Dodge Viper and a Toyota Prius.

[Satoru @ Apr 11th 2006 10:04AM]

The original Cnet article was like comparing a Hybrid Ford pickup with a Honda Civic, then coming to the conclusion that hybrids don't save you gas. They were comparing completely different technologies. While not exactly a in-depth study its still had better methodologies than the Cnet article. It also confirms pretty much what most people had surmised, which is that DRM by itself isn't draining your battery into oblivion.

Now I'm not saying that I LIKE the idea of DRM. However I think we should concentrate on the actual harm and social implications of DRM. More fear mongering about it simply gives the trolls more stuff to whine about.