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Definitely engineering.

Optimizing battery life is like f(x) = 1/x

If there is a way to get your standby power down to 0, you have infinite battery life. (Theoretically!)

If OSX really gets 2x the battery life of Windows, they only had to squeeze out 3.3 Watts. (calculation below)

So Atwood points to the 2013 Macbook Air 13", and its "14 hr 25 min" battery life. Well something fishy is going on there. He cites [1] but Apple themselves only claim 12 hours [2], and other tests have come in just under 12 hours [3].

Here's how I derived the 3.3 Watts above: the 2013 Air has a 54 Watt-Hourr battery.

  54 Wh / 7 h 40 m = 7.043 W
  54 Wh / 14h 25 m = 3.746 W
  Save 7.043-3.746 = 3.297 W
Keep in mind Watts measure power, not energy. So to save 3.297 Watts average, OSX is keeping something mostly turned off that Windows is not successfully keeping off. OSX is saving on average 3.297 W over the test period by having brief bursts of activity while staying mostly idle.

It isn't surprising at all that Windows isn't able to fully manage power on a system that hasn't had its ACPI tables set up specifically for Windows (beyond getting Windows to boot).

I'm happy to say I've been Windows-free since 1997, no love lost and never looking back. But the statistics presented here have some major flaws. More testing / engineering needed...

[1] http://www.digitalversus.com/laptop/apple-13-macbook-air-201...

[2] http://www.apple.com/macbook-air/features.html#battery

[3] http://www.tekrevue.com/2013/07/28/pushing-it-to-the-limit-2...




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