DRM shortens battery life by 25%

I performet a little experiment of my own a few weeks back - using a Toshiba Gigabeat, I juiced up the battery to full, put a few CDs on it and played it non-stop at work until it died.

I was disappointed by the short battery life, so sought to remove unnecessary processor overhead. As a programmer, this was the natural first step.

I transfered the same tracks, unencrypted, in the same 128-bitrate MP3s I'd used before, and the music lasted all day and battery was still showing at full (but the Gigabeat only has three battery displays: all green, half green half empty, and "almost dead").

In any case, I tested regular MP3s against DRM MP3s and found battery life to be about half again as long.

Eventually, I might add, I did a little bit of firmware hacking to strip out excess features, allow OGGs, and now I can go two days or more without a charge. But that's kind of beyond the scope of this topic.

There's probably something to it, but CNET's test was flawed. They compared protected ACC tracks to MP3, and Protected WMA tracks to MP3. That won't show what the DRM schemes alone can do.

A proper test would have compared protected vs. unprotected files *of the same format*, not completely different formats. For example, compare Protected WMA files to Unprotected WMA files, and Protected AAC files to Unprotected AAC files.

An interesting *format*-related test, not a *DRM*-related test, would be to compare battery life with 128-bit MP3s vs. 128-bit WMAs vs. 128-bit AACs...

...but jeez, do a proper test, don't compare THREE factors and conclude that your results are exclusively due to ONE of them.