Check to : See if Multi-Processor Support is turned on. Multi-processor support feature may be disabled depending on your setup (it was for me) - you can check this by launching Firefox, then enter in "about:support" in the address bar; near the bottom, you should see a heading that says: "Multiprocess Windows", then look at the value next to it. If it says "0/1", then that means it's disabled. 0/2 and higher = on unless says it is off.

Then check the Task Manager and see how many instances of Firefox is running and what the memory numbers are like.

If need to can turn off multiprocessor : You can try to modify multi-process settings to see if this has effect. You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

set dom.ipc.processCount to 1 if it is currently set to a higher value (4) disable multi-process windows in Firefox

You can disable multi-process windows in Firefox by setting these prefs to false on the about:config page.

browser.tabs.remote.autostart = false browser.tabs.remote.autostart.2 = false

http://kb.mozillazine.org/about:config Also can reverse everything this tells you to enable it. http://www.ghacks.net/2016/07/22/multi-process-firefox/

Please let us know if this solved your issue or if need further assistance.

Hmmm... I have a 0/1 reading in help:about. browser.tabs.remote.autostart already = false, but browser.tabs.remote.autostart.2 was true, so I changed it to false . Right now, memory seems lower, and I see Firefox (2) in Task Manager. I don't recall seeing (2) before I made the one change, but I wasn't looking for it, so I could be wrong.

Of course, it's too soon to tell if the one change I made is making a difference. The problem generally builds during the day, so I guess I'll have to just observe during the day and see if this helped.

I guess maybe I should see if I can find out exactly what "multiprocess windows" are to make this more understandable. I'll get back to you one way or the other to see if I need more help -- or if I should just consider using a different browser, which would make me very sad since I've been using FireFox for many years without issues. I've been on anew computer and in Windows 10 since about May, for the record.

Thanks.

So, it's been a few hours since my above post -- and since I used the computer for anything. Even though nothing has changed, the memory usage has jumped to 57%, and it's all coming from Firefox -- just like before I made the multiprocess window change.

I still think that recent updates have introduced memory hogs into Firefox.

You did restart Firefox after making the change ?

Can you live with the issue until Firefox 57 Quantum Release Nov 14th ?

Can check if this makes any difference : https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems?redirectlocale=en-US&redirectslug=Troubleshooting+extensions+and+themes

Note : Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed.

Yes, I restarted. If I get time later, I'll check out the suggested link. But, the Quantum release give me some hope since it appears like it may address the memory issue. I've dealt with it this long, so I can certainly wait a few more days.

Keep your fingers crossed that this will help. I really would prefer not to start with a different browser. Thanks!

Turns out that the new Quantum version is operating within the memory parameters of Chrome, which I installed out of frustration. It's only been an hour so far, but it looks like the new software was the fix. I recommend that anyone with a memory-eating problem download Quantum. Believe me, it's easier than setting up and getting used to a new browser!