The solution is to rebuild Firefox to use Core Animation to draw the window contents and then send only changes to that content to the graphics compositor after that instead of using the long deprecated OpenGL implementation it currently uses that repaints the whole screen over and over, so it's hardly surprising to see such a massive change take quite a while to implement.
The earliest changes in this process have finally made it into beta and there are already substantial improvements in power usage/heat generated by an overworked GPU even before all the changes in progress have been enabled.
Glad to hear that there's finally progress being made!(or if it has been on the way all this time, glad to see that it's finally getting to the point where final users can see a difference).
Are you involved in the fix? If so, do you have a rough ETA for the remaining changes?
I've just been reading the bugzilla discussions on the issue since back when people were first trying to figure out what was causing the issue.
pcwalton is involved in the fix, and as he mentioned, really significant improvements are starting to land for testing in nightly with more fixes yet to come
The earliest changes in this process have finally made it into beta and there are already substantial improvements in power usage/heat generated by an overworked GPU even before all the changes in progress have been enabled.