On the other 27 iMac, I updated to FireFox to v. 41.0.2.
And it makes the CPU chug and the computer makes a lot of noise. Restart puts it all OK again. But after leaving FF on for a couple of days, it starts cranking up again.
Any idea what is going on? I like FF and want to use it again.
Saw on the web to uncheck "use hardware acceleration", so I did. See if that helps. I should go back to 40.0.3 and see if FF stops this cranking up.
On this 27 iMac, I stuck with FF v. 40.0.3 and its working fine. Yosemite here too.