SamBerry, I also used to hate any browser that created a ton of processes but I changed my mind a few years back when I realized it made all the browsers more stable. If one tab goes crazy/haywire, it can't crash the entire browser & wipe out all the tabs anymore. Only that single tab will crash & it can be reloaded w/o restarting the entire browser. I believe it also provides some extra security by isolating & sandboxing one tab's contents from another.
All modern browsers have multiple processes now. That's the future of browsers until they come up with something better years from now. Chrome also creates a ton of processes for each tab & so does Edge, Brave & Vivaldi.
Do I still hate seeing tons of extra processes in my Task Manager? Yes! So what do I do about that? I make sure to open very few windows & only have a few tabs in each window. If I go overboard once in a while, I make sure to kill as many of the tabs & windows I don't need before I put the desktop/laptop to sleep. That's the only true way to keep any browser in check & from stealing a ton of your cpu & memory.
Your point about 100% CPU usage is very fair though. You gotta start trying to see which sites the high cpu usage is coming from & also try browsing with your addons disabled, by turning them off one by one after going thru a browser session with each addon disabled. Or turn them all off & slowly enable them one at a time while checking Task Manager. It sucks but that's the only way to narrow down the true cause. Then you can focus your rage on the addon or website responsible for always giving you 100% cpu.
Reponse to Ag:
Ag, I took a look & it appears 3 tabs are running the CPU very high at 26%, 14.6% & 20% + the top 2 processes that belong to 2 tabs seem to be using ~2,300 mb & ~1,800 mb. So I'd like to help solve the mystery but ANY time I respond to a post like this, I NEVER get a response back. I'm really curious if we can solve this by just disabling 1 addon that's being very aggressive or 2 addons that are maybe fighting each other on those tabs.
Example high cpu addon, LastPass. One person noticed horrible performance with it enabled & once disabled Firefox ran normally!
Which sites are loaded in those tabs too could really solve the mystery too. As I've seen many times Facebook go crazy & cause high memory & high cpu for tabs because they use a ton of scripts.
If you guys want to do more troubleshooting, you can post a support question here:
https://support.mozilla.org/en-US/questions/new/desktop/form
