Yes, I also observe much more power drawn even on a single page (especially if it contains animations) opened in Firefox vs any other browser, and on Windows, IE is significantly less power hungry.
I've also checked this newest version, 70 on Windows and my measurement of the power use give practically identical results to the measurements I've done almost two years ago.
I see that the power drain comes from the browser's own code doing something unnecessary and as far as I see it doesn't even appear to platform dependent.
It's surely possible to optimize that and it's obviously not their priority.
If you would share any of your findings, I'd be interested to see that.
From what I've read, Mozilla can't really optimize rendering to the level of Safari & Edge. I found this article[0] on WebRender to be very interesting on this front. The author noted-
"Note: Painting and compositing is where browser rendering engines are the most different from each other. Single-platform browsers (Edge and Safari) work a bit differently than multi-platform browsers (Firefox and Chrome) do."
I love Firefox quite a bit, every detail, the way it scrolls with smooth scrolling off, the dedicated search bar for switching DuckDuckGo bangs, the container support. The dedicated search bar is a huge one, I can't imagine why no one else at least offers that, as a feature it can't cause that much maintenance headache. I definitely love FF as much as anyone here but I'm not one who argues that Gecko is necessary for a standards-based web, I'm not convinced by the argument. Webkit can be forked again and it has a significant userbase to act as a counterweight to Blink. It's increasingly difficult at this point to convince myself that native browsers don't make the most sense.
My notebook happens to have a fan calibrated to turn on when the CPU gets "too hot" where the point is above of what is consumed by IE to show the pages with more videos, so I actually hear the power consumption of Firefox and I simply don't hear it for the same page when opened in IE.
So for me is simply: open some page, hear the fan for as long as the page remains open. Do the same with IE, silence.
BTW I otherwise haven't IE used for daily browsing, but I did a lot of tests with the same pages to see that it's not an accident and that IE does show the same content, but with less power used.
For somebody with a different computer: find any web page with more media playing on the page (you should see the videos playing or pictures "animating"), open the task manager (this is a Windows example) then switch to the graph view and compare the browsers while looking at the graph view. The task manager area "under the curve" reflects the power used -- the more CPU used for a given amount of time -- the more power used. In my observations the area drawn by Firefox is more that twice as big as the one by IE.
That's what drains the battery faster: taking more CPU to keep the "animations" on the page. Moreover Firefox has some consumption created by some of its background tasks even when the pages aren't animated, but the animations are really wasting a lot of power.
From my look at the behavior, having some experience in evaluating the performance of the software, and spending some time trying to figure out what's happening there, my impression is that the source of that power drain is in the Firefox code which is not platform specific which explains why they have problems on every platforms with that.
I've concluded they simply never actively tried to minimize overall CPU and GPU use (both will use more power unless somebody measures and tries to improve the code): even when they did move some pieces of processing to the GPU, their motivation was speeding up what's visible, actively minimizing the power used was simply not the part of their process.
You can also search their Bugzilla to see how they handle the problems with the CPU, GPU use and the power drain. This can be a part of the workflow, measuring that at least for every release and acting to fix the issues, but I just don't see that anywhere.
That's essentially how I've been A:B testing as well. I was hoping you had some software that measured power draw and tracked it. Much like the Windows 10 power usage info. A laptop fan is a pretty good arbiter.
Agreed though, it's very noticeable and I never did feel it until I started using a laptop more than a desktop. I'm also finding bugs in the iOS version of Firefox which is probably going to be the last straw, not only does it freeze often, my bookmarks are no longer there and they were synced from my Firefox account. I'm likely to migrate to native browsers for whichever platform I'm on at that time. As you said in their own process they're focused on feature development but not efficiency. Overall, I'm losing faith that Mozilla has the resources to effectively manage all of this.
I hate to followup with a 2nd response but I wanted to add, it really would be a poor priority anyway because they'll never be able to beat Apple or MS at optimizing a browser for their OS.
My advice to Mozilla would be to continue on the customizability and privacy route, and get Firefox on iOS in better shape. It's been freezing on me for as long as I can remember using it. Very buggy, and has played a significant role in losing some confidence in Mozilla.
This message and all of my messages in this thread posted from Microsoft Edge 78.0.276.20 (Official build) beta (64-bit).
I've also checked this newest version, 70 on Windows and my measurement of the power use give practically identical results to the measurements I've done almost two years ago.
I see that the power drain comes from the browser's own code doing something unnecessary and as far as I see it doesn't even appear to platform dependent.
It's surely possible to optimize that and it's obviously not their priority.