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Comment by suprgeek | Hacker News Reader

Please please test battery life impact while implementing the Multi-process stuff.

I had to move away from Chrome just on the battery life issue. I suspect (but cannot conclusively prove) that the multi-process crap that Chrome has just drains your battery much faster. And yes I am perfectly aware of the supposed fix in Chrome for the battery killing bug.

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There's no inherent reason why multiprocess would have a significant impact on energy, it just adds a relatively small amount of extra context switching and marshalling to what is already a huge pile of the same (your desktop OS). When the system is idle, or a page is rendered, the difference shouldn't be measurable.

Hypothetically, 50 processes all running separate unsynchronized wakeup timers and event loops could bring the processor out of sleep 50x more often than a single process.

I assume all graphics data is sent from the tab sub-processes to the main process (Chrome and similar in IE9-11). Multiprocess is different in Firefox, to get full multiprocess (per tab) we maybe have to wait a bit longer, for a Servo based browser.

Launching processes is a bit expensive especially on WinNT series (up to Win10), but ultimately it's the way to go ("sandbox" = sub-processes with minimum permissions) - even Servo with its Rust language use it as certain parts like the JavaScript engine are still C/C++ based (come from Firefox/gecko) for the near future and can crash.

If you were on windows and on chrome before 39 (I think), the battery bug was often because chrome forcibly set the system clock tick rate higher than (arguably) necessary. Should be fixed now though at least according to the bug tracker

They made some battery improvements on Windows, but it's still a huge battery hog on Mac.

Safari is multi-process and it has the best battery life.

It is a bit of a memory hog as well, but yes, it's battery life is just fantastic.

Safari makes use of a kernel feature that allows giving some leeway for when the process should be woken up again (eg. from a timer source). That way the kernel can put the CPU to sleep until it can schedule as many processes as possible at once to wake up and perform their work. That way the CPU doesn’t have to wake up all the time to wake up a single process and let it do its work.

Windows and Linux should be able to do that, too [1] - any idea if Chrome or Firefox make use of it?

[1]: http://en.wikipedia.org/wiki/Timer_coalescing

Yea I am with you, I love Chrome and I love that its basically my little mini xplat OS. That of course comes with a price of being a battery hog, if you don't want to use all the benefits Google is cramming into their browser, then I can see the allure of FF. I imagine that represents a fair number of FireFox's users as well. I imagine they won't abandon you friend. :)

Battery life on FireFox is good if you use "lazy tabs" feature. If you need more battery, you just restart the browser and it only loads the tabs you open, so the old ones won't have JS working.

Do you have data on Firefox using less battery? I thought the order for energy usage was Safari < Chrome < Firefox (but can't find anything to back that up either).

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