Michael Murphy :
People here are really dumb and do not understand how RAM works. It is better to have your browser to consume as much RAM as possible, this doesn't mean that this RAM is being 'actively' used. If you have 2GB of RAM and it is taking up 1.2GB of RAM then guess what, none of your programs are using up more than 0.8GB combined. If you were to launch an app or game that did need RAM it would simply dump all the 'passive' RAM Firefox is using. In other words, more RAM = speedier browser, less RAM = more loading time to get the cache back into RAM.

morcxz04 :
but less available ram causes the whole system to freeze and run slow ryt?

Vesselin Obreshkov :
Not really. Maybe in Windows 9x days but not today. Unused RAM = wasted ram (not only on Windows, Android works much the same way and people complain about it using too much RAM all the time when in fact it is simply managing free RAM in the best way possible, hence why Task Killers on Android are one of the most useless apps but people still use them because of this misconception). Windows manages RAM way differently than what most people think. Like Michael said, if your browser is using 1Gb of RAM, that is because nothing else is using your free RAM. As soon as you launch a program (or Windows itself needs more RAM for something) then the extra 'passive' RAM used by your browser (Firefox/Chrome/IE/whatever) will get freed up instantly and handed over to whichever app/process needs it. Try it out yourself. Open Firefox and open up a bunch of tabs and see how much RAM FF is using. Then start Photoshop, Word, Excel, etc and see how much RAM Firefox is using all of a sudden without you closing any tabs or doing anything. So the moral of the story is that if your PC runs fine when you have all your commonly used apps running then leave it alone and let it do it's thing. However, if a rogue app still keeps eating up your RAM when you have your other apps running as well then go complain to the developer to fix their extensive memory usage.