Thanks for the info Tim!
Glad to see you here!

It is not only power draw needed to execute a task that is important but the time period of drawing that power while executing the task as well that will actually affect your battery life. So that you can know the total amount of energy drawn during the completion of the task.

Ryan Shrout the editor of PC Perspective actually did some sample tests of measuring power usage over time comparing the VIA Nano and Intel Atom:

“Using the same method to gauge the results of our CineBench 10 test, we find that the VIA Nano used 63,434 watt-seconds (Joules) of energy to render the scene while the Intel Atom used 65,893 watt-seconds (Joules) of energy - an advantage of 3.8% to the VIA CPU.

These kinds of power comparisons are incredibly insightful and you can clearly see how both teams of CPU designers have made trade offs for the either power consumption or speed. The VIA Nano L2100 is able to perform these tasks faster (by as much as 30% in some cases) while still using less total energy than Intel’s Atom. ”

http://www.pcper.com/article.php?aid=597&ty...

So in most “real world” usage scenarios… Nano also beats Atom with less power consumption.

Power consumption/TDP/ is a tricky area that most people don’t understand well.