If DRM isn’t evil enough, testing now shows that it shortens a player’s single charge playback time by up to 25%. Why you ask? The DRM forces the player to work a little harder and decrypt the music files on the fly thus sucking down vital playback juice. CNet put the proof in the pudding by testing a Creative Zen Vision:M with regular MP3s, resulting in 16 hours of playback, and then with WMA DRM files which resulted in 12 hours of playback.
Good news is that Apple’s Fairplay DRM only reduced battery performance by 8%, but reduced nonetheless. CDFreaks points out that this results in more often charging the device and ultimately shortening the life span of the battery. For non-rechargeable players this means a 25% increase in battery cost.
DRM Shortens Battery Life by 25% [EHomeUpgrade]