1.
Type in "about
:config" into the address bar and press enter, and agree to be careful.
Right click anywhere and choose New > Integer.
Call it
browser.cache.memory.capacity
You?ll need to enter a number in the Enter integer value, but that number depends on how much memory you have (specifically, how much you want to "give" Firefox). If you have 256MB or less RAM, enter 4096 as the value. If you have 512MB of RAM, enter 6144 or 8192.
2.
Type in "about
:config" into the address bar and press enter, and agree to be careful.
Right click anywhere and choose New > Boolean
Call it
config.trim_on_minimize
What this does is, no matter how much memory Firefox is currently using, when you minimize it, it will shrink right down to 10mb of used ram! It'll slowly creep back up to 50mb but not exceed that.
Then when you restore it, it'll stay at or close to 50mb.
Restart Firefox after you've added these values.
