A recent Cnet article reveals just how much extra processing power is used by your MP3 player in decoding DRM (Digital Rights Management). It’s just another reason to rage against the DRM! It seems that playing back MP3s encoded with a DRM can reduce your battery’s life expectancy by as much as 25%.
When looking for an Mp3 player you’ll usually see an important specification like this.
It means that off a single charge this MP3 player will run for about 12 hours. According to the testing that Cnet performed most manufacturers give an honest assessment of their battery’s charge. Most will meet or exceed the posted spec but only when running under the most optimal conditions. When testing Creative’s Zen Vision: M Cnet found it exceeded its posted spec by two hours. It was rated to last 14 hours but in testing it actually lasted 16. When fed a steady diet of .WMV files encoded in Microsoft’s DRM 10 known as PlaysForSure the Zen Vision MP3 player lost 25% of its playback time and was only able to play for 12 hours.
Sure, 12 hours is a long time for a single charge. Rechargeable batteries have come a long way in recent years to where most people aren’t concerned with a lifespan of a single charge lasting anything over eight hours. But consider that many MP3 players don’t have user replaceable batteries. You have to send it back to the manufacturer to have a dead battery replaced. All rechargeable batteries only have a finite number of charges in their life. Apple rates the iPod to about 500 charges before it needs to be replaced and you have to send it back to Apple for that replacement.
The worst DRM is PlaysForSure that encodes WMA files you can download from the online music services such as Napster or Yahoo music. These are subscriber services, as long as you’re subscribed you get to download the entire library of songs available and play them back on any DRM 10 compatible device, such as Creative’s Zen line of MP3 players. The trouble is that the DRM must check validity of your subscription, as well as the device it’s trying to playback in. These kinds of checks through the DRM require power from the battery and will drain the life from it.
Apple’s FairPlay DRM is also guilty of costing battery power too but not as much. It was discovered that MP3s downloaded from Apple’s iTune (all of which are encoded with FairPlay and can only be played back in an iPod or iTunes desktop application) will reduce your iPod’s battery life by about 8%.