I wonder what's causing that on your computer, because I'm running Firefox on a late-2011 MacBook Pro without any issues, and that's with a ton of tabs opened (including a bunch of pinned tabs running multiple instances of Office 365 in separate containers, Slack, and so forth) and the usual crowd of extensions (UBO et al). It's bouncing between 0 and 5% CPU utilization.
I've tried figuring it out, but haven't been able to pin it down. Is it even possible to check tab resource usage the way I can in Chrome? If not, that's another reason I'd probably keep coming back to the latter.
Thing is, it's not even that I have so many tabs open. It's always been fewer than Chrome, and with fewer active extensions to boot. Furthermore, it also happens on my other computer. The other one has 16 Gb of RAM, so it can handle quite a bit more, but the problem happens often enough that I also switched back to Chrome there.
I had to stop using FF on windows when it tanked because I disabled hardware acceleration (to force google maps to stuff their stupid 3d satellite images in the can). Look at the your rendering settings would be my random guess.
I experience regular "gray outs" on Ubuntu with FF hogging so many resources that eventually the only thing that works is killing it. This happens to me both on a 5 year old desktop as well as on old Lenovo Thinkpad (X2002s). However, I believe flashplayer to be the culprit as I often have quite a few youtube tabs open -- obviously never more than one playing though.
Why are you using Flash Player for Youtube? I've gone nearly 4 years since installing Flash on any machine, its pretty well unnecessary today. If you want to reduce performance though, using Flash is one way of going about it.
It’s usually the profile (some tweet years ago, some bad setting ) would be great if Mozilla had some solution for this other than zap your profile. Alternatively it’s an addon they have.
