In the Zune 120, the main design change is the use of a new 120 GB hard drive. The Zune 120 uses Toshiba's new 1.8" MK1231GAL hard drive. When the drive was released, Toshiba claimed the new hard drive would reduce energy consumption by 20% during read and write cycles. Playing videos and and downloading music over wifi, would count as using those read and write cycles respectively. Compare this to the 'energy consumption efficiency' of the Zune 80's MK8009GAH 80 GB hard drive and, on paper, the energy savings are apparent.

According to the numbers on Zune.net, Toshiba's claimed energy efficiency improvements could be demonstrably true. The website states the Zune 120 will get up to 30 hours of audio playback with wifi off. At the same time, Zune states the Zune 80 has a 24 hour run time, with the same conditions. When comparing the battery life totals, the Zune 120 comes out with a 25% improvement on battery life. That seems to confirm a hypothesis that a 20% reduction in energy consumption could directly lead to a 20% (or better) improvement in battery life. Trusting Rapid Repair's post mortem report, we can assume all other hardware factors to be the same and credit the efficiency improvements to the new hard drive, making the hypothesis true. For the time being, I am going to ignore the effect of potential power optimizations built into different versions of the Zune device firmware.

In trying to quantify something I had speculated about previously and seeing the 25% increase in battery life as having a strong relationship to the 20% decrease in hard drive energy consumption, I have come across something odd. In October of 2007, Zune Insider stated (picture -- in case things change) the Zune 80 had the ability to playback 30 hours of audio. A February 1st, 2008 web archive of Zune.net says the same thing. Web archive posts are delayed by roughly 6 months. In November 2007, CNET could not replicate those 30 hour claims. Instead, they attained only 22 hours of audio playback. CNET has not released any battery life testing results for the Zune 120.  CNET's result of 22 hours is closer to the new 2008 battery life of 24 hours. The problem is, this conflicts with the 30 hour capability originally claimed in 2007. In the move to Zune 3.0, how did the Zune 80 officially loose 6 hours of battery life? Comparing the Zune Insider announcement of the Zune 30's capabilities and looking at the web archive from the same February 2008 day, reveals no change in battery life. Since the move to Zune 3.0, the Zune 30 is no longer listed on Zune.net, viva la Zune 30 (<-- last chance!). *Update: Using a Zune 120 Cnet achieved 32 hours of audio playback with wi-fi off.*

While the new numbers seem seem to support Toshiba's efficiency claims quite well, can they be trusted? These tests are probably run under 'best case' scenarios, yet when considering the above facts, it is likely the Zune 80's original battery life numbers were inflated for some reason. If so, where is the announcement about a testing mishap or reduction in playback capability accompanying the bump down to 24 hours? Taking a bit of a slippery slope stance, perhaps it is fair to assume that Zune 120's totals are inflated as well? Hopefully Cnet, or another independent source is willing to test the two devices under similar circumstances to see if the new 120 GB hard drive does have a positive effect on battery life or whether any gains in efficiency are lost due to the extra 40 GB in tote when compared to the Zune 80.

Microsoft used to have a support article stating how to test the battery life of your Zune. Currently, I cannot find it. If you can find that article, or can find the testing circumstances under which Microsoft achieved 30/24 hours for either Zune, please post them in the comments.

What do you think, marketing mistake, engineering error, or something else entirely?

 

Edit: I've updated the article to reflect the new battery data as provided by Ricardo Dawkins via Cnet. Thanks for the heads up Ricardo!