I suspect that's the real reason why Apple is weighting wakeups heavily and exaggerating the energy impact: it shames developers into making their apps more efficient.
Except Chrome, which on every laptop I've ever used seems to decrease battery life by about a 1/3rd compared to Safari and is always marked as using significant power.
(Currently 10.9.5 with chrome 44 on a 2014 macbook air, but I've had the issue on newer computers at work)
This can be seen exceptionally when watching videos where some implementations prefer Flash. I often fall asleep to documentaries (maybe not a typical use case) and I've seen massive gains in battery life using Safari (using HTML5 video) vs. Chrome (using Flash). Granted, this isn't a fair comparison as one is using a "native" implementation and one is using Flash. But I've seen something like 250% gain in battery life – which sometimes means the difference between seeing the ending and not.
It's interesting watching one's projected battery life climb from 40m to 1h 40m simply by swapping one application for another. However, it's unfortunate some websites prefer Flash-based implementations over their native counterparts. Although this trend seems to be shifting in favor of those that are native. And I assume the smart folks at Google are taking note. YouTube, for example, has done a particularly spectacular job at adding AirPlay functionality to their HTML5 player.
My guess is that native HTML5 is just h.264, and most modern systems have a hardware decoder that would be much more efficient at decoding than a software implementation. Flash video is a wrapper around a number of codecs, and if the codec isn't h.264, then you're doing software decoding, which is far less efficient.
There is currently no good browser for apple. Safari (8.0.8) struggles with HTML5. Firefox (40.0.2) struggles with video/media of any sort and bogs down with multiple tabs. Chrome (44.0.2403.157 (64-bit)) drains your battery. I'm on a MacBook Pro (10.10.5, 13-inch, Early 2015). They are all uniformly disappointing.
At least for me, that's partly because Chrome makes it _so_ easy to "overuse" it. I'm right now writing this comment in a window with 29 tabs open, I have three other chrome windows with 22, 17, and 14 tabs open respectively. It's sitting there at 42.3 in the Energy Impact column and 32.23 in the Avg column - but to be fair it's got a whole bunch of stuff going on (two separate gmail instances and a fair few other javascript-heavy webapps as well). I've probably go more bogomips going on in this one browser window that all the machines I learnt to program on were capable of between them...
Hmm… comparing that to the amount of tabs and windows I have open in Safari right now (which is actually pretty low for me since I usually have more than 250 tabs open) seems to make Chrome look even worse…
Specifically (running Safari v7.1 on OS X v10.9.5), I have 18 windows open containing 2, 18, 26, 16, 2, 12, 17, 13, 21, 6, 2, 2, 1, 1, 2, 1, 1, and 4 tabs for a grand total of 147 tabs. Oh, and I forgot to mention, it’s also downloading two files in the background right now. It’s showing up with 13.2 in the Energy Impact column and 4.47 in the Avg column.
(Oh, and since I already have it open, I may as well mention that Firefox 39.0 shows up as around 14.7 in the Energy Impact column (although it keeps spiking to 23.9 every few seconds) and 2.99 in the Avg column with 2 tabs open in 1 window with no downloads).
I'm at 47.91 average impact for FF 40.0 with uBlock Origin and Ghostery, no Flash installed. Doing local web development and poking around some news sites to read about all these market crashes. Only a few tabs open at a time for me.
If your a developer at Google that is looking for a 20% time project here is your opportunity! Make some fixes, write it up and post about it somewhere and we will up vote your story and give you sweet HN karma. :)
Adding info because I didn't understand the reference. https://en.wikipedia.org/wiki/Cobra_effect "The cobra effect occurs when an attempted solution to a problem actually makes the problem worse. This is an instance of unintended consequences."
Because I'm the author of the post that this comment thread is about, and one of my primary conclusions in the post is that "Energy Impact" is inaccurate.
I am not sure they are weighting wakeups heavily. "but with a “tax” of 500 microseconds for each wakeup" could be a reasonable estimate of the time the OS needs after wakeup before it can hand over the CPU to the process that did the wake up. That time isn't spend in the process that wakes up the system, but can be attributed to it.
The article discusses this. Look again at the first table. Compare the power values (measured in Watts) which climb slowly, vs. the "Energy Impact" values which climb incredibly quickly.
If "Energy Impact" was a good measure it would correlate closely with real power consumption. It doesn't.
