Firefox using more RAM than it says it is
I recently upgraded my total RAM on my Macbook (10.7.5, 4 years old) from the default 4 GB to 8 GB because my computer was basically inoperable. Applications were crashing, it took forever to transition between applications, and I needed about 15 minutes to kill 3-4 applications (Firefox, iTunes, Word, Excel) and do a hard shutdown. When I upgraded, things were working much better. However, I am experiencing a different problem now (perhaps this was happening earlier, but because I only had 4GB RAM that was always maxed out, I was never able to notice it). When I have Firefox running initially, I have around 4 GB RAM free. However, after about a day of running without opening new applications, I end up with 0 GB RAM free. Even more confusingly, in Activity Monitor, Firefox (while increasing some, usually from .7 GB to about 1.5 GB) does not register to be taking up 4 GB. Firefox takes up an order of magnitude more RAM than my next largest application (Word) (so the change cannot be with some other application), but somehow this change is not being recognized.
I have isolated the problem to Firefox because, when I run out of free RAM, I close Firefox, and all of a sudden I have over 4 GB RAM free, no matter how much RAM Activity Monitor claims Firefox is using. And even more confusingly, when I reopen Firefox with all the same tabs, everything starts out anew, with Firefox using about .7 GB RAM, and leaving me with 4 GB of free RAM. I have talked to Apple about this, but they cannot find anything wrong with the machine itself, and say it is solely within Firefox itself, and they don't have access to any troubleshooting about non-Apple software.
I have gone through the list of fixes already provided on the Mozilla website. I have the latest version, do not have a theme, only have two plugins/extensions (Adblock Plus and Disconnect). This problem exists whether I run 3 tabs or 30 tabs. I don't really use flash all that often so I don't think that has anything to do with it. Any thoughts you have would be extremely helpful! (N.B. I'm rather technically backwards, so I may not understand technical jargon without explanation!). Thank you so much!
All Replies (2)
Adblock Plus is notorious for using too much RAM, it's possible another extension (such as ublock origin) may be better suited to you as they use less memory.
Also, have you tried checking out about:memory in Firefox? You can see your actual memory usage there.
I'd also suggest you update to Mac 10.10 if it's available for your system, changes in 10.9 and 10.10 make Mac much smarter about using less memory (plus they are more secure and free)
I have just looked into about:memory, but I don't know how to properly read it, figure out where I am using more memory than I should be, and correct it. For example, if Adblock Plus is the problem, I don't see a branch on the tree that is any more specific than "add-ons" (which are using about 3% of my total explicit memory).
As far as I do understand the tree, it appears that, within "windows objects" (44% of memory), gmail is taking up about half of that 44%. To some extent this is expected, because I am using gmail a lot. However, that's a ton of memory allocated for one tab. I have gmail pinned; do pinned tabs have anything to do with this?
Thinking about alternatives to Adblock Plus, I actually haven't heard of ublock origin. I'll be looking into it more, and if the problem persists/I like what I see about ublock, I'll switch. Thanks for the recommendation!