Microsoft’s WMA saps battery life by 25% vs. MP3 format

“When users take the specifications of an MP3 player into consideration, one very important factor most take into account is the rated battery life. However, as many are aware, the battery life stated is generally the runtime from a full charge in ideal conditions, such as when the player is left playing without any sound enhancements (EQ, bass-boost, etc.), volume set to a moderate level, all music is 128kbps MP3, backlit display goes out within a few seconds and so on. However, according to tests conducted by CNET, they found that while many players met or exceeded their claims, one feature that has a drastic affect on battery life is the infamous DRM,” Seán Byrne writes for CD Freaks.

“When it comes to the Creative Zen Vision:M’s 14-hour claim, CNET got about 16 hours of playback time with MP3s from a full charge, which was a nice surprise. However, when they tried playing WMA 10 DRM crippled subscription tracks on it, they only got just over 12 hours; a loss of almost 4 hours (~25%) of playback time due to the battery-hungry DRM. CNET found similar results with other players with WMA DRM drastically reducing battery life by up to around 20%. Apple’s FairPlay DRM seems to have less of an effect with battery life being reduced by around 8% when compared with MP3 playback,” Byrne writes.

Full article here.
This doesn’t tell us that DRM is battery-hungry. This tells us that Microsoft’s Windows Media Audio (WMA) is horribly inefficient and causes the processor work so hard to decode that it saps 25% of battery life versus playing MP3 files. Advanced Audio Coding (AAC), which is used by Apple, is more efficient than Microsoft’s WMA (big surprise, huh?), causing an 8% battery hit versus playing MP3 files. So, this test is about codecs, MP3 vs. WMA and MP3 vs. ACC. To test whether DRM affects battery life, unprotected AAC files need to be tested against protected AAC files and unprotected WMA files need to be tested against protected WMA files.

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  1. Shouldn’t Apple actually indicate this advantage in some way especially as it would by definition show the superiority of AAC over WMA. It can’t be less accurate than Sony’s totally misleading claims for the rediculous number of tracks supposedly loadable on their players, nor Microsofts laughable claims to be on top of security in their adverts for that matter. After all it rather blunts the supposed superior battery life of most of the opposition, the one area where the iPod generally is at the lower end of performance and certainly made me personally wonder about the relative efficiency of AAC and might just tempt away some users with similar notions.

  2. nice take MDN — CNET demonstrates its ineptitude once more. The author over at CDFreaks should have pointed this out.

    Don’t we generally learn about controlling for the right variable in grade six science?

  3. Moron, er, Copernicus:

    The slant is not “idiotic.” The only thing “idiotic” about this is your response. Try reading it slowly and attempt to understand the point, you dunce.

    MDN MW: “policy” – It is not usually my “policy” to publicly correct and demean the retarded, but in this case, I must make an exception.

  4. The only problem I have with AAC formate it doesn’t retain the album info when ripping a burned cd to another mac.

    I could be wrong but I thought only MP3 retains album info.

  5. MDN makes a good point about comparing apples to apples etc. as did one of the original posters at Actually what this article is saying is that DRM requires extra power to read the DRM protected tracks. If this is true (and more testing needs to be done) then this is dynamite. This may mean that DRM of any flavour sucks the life out of your music player’s battery. The obvious solution is to steer clear of DRM encoded music.

    Now I’ve been attacked for using sites that in all probability may NOT pay a remittance to performers but I made this decision for two reasons and two reasons only:

    1. I hate DRM and won’t touch it with a barge pole and

    2. The bit rate at iTunes Music Store is just too low

    So I use It serves my needs and I purchase AAC songs @ 320 kbps which I then rip to the ipod(s) at 224 kbps. I can also do this from cd collection but I can’t do this from practically every on line music store. Why? Because of those bastards from the music companies that’s why!

    If Apple and the others ever fix the two aforementioned points I’ll whip out my Visa card quick smart…and Apple’s store would be my only choice. But I’m not holding my breath for any change any time soon.

  6. I didn’t have time to read the whole article yet, so maybe it’s in there, but I’d be really curious to see what the difference in battery life is when they encode music from a CD to WMA (in other words, no DRM) vs. MP3.

    Microsoft should really just get out of the codec business all together.

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