Firefox’s Memory Usage

I used Firefox daily until Chrome came out. I switched right then and there. I used Chrome on Windows and Linux and totally shunned Firefox. Recently Chrome had been using around 600MB of RAM which is a lot for only having 3 tabs open. So I went back to Firefox. I tried out Firefox 4 beta and it worked out but I need some extensions to work such as Firebug. So I uninstalled Firefox 4 and installed Firefox 3.6.8. So I installed Firebug and went on with my daily usage. Fast forward to today and I find Firefox being unresponsive. So I open up the Task Manager and what do I see? Firefox using 1.6GB of RAM making my total RAM usage 2.6GB. I kill firefox.exe and my usage goes back down to .98GB. What a huge difference. Needless to say I’m back using Google Chrome and just waiting for Internet Explorer 9 to come out.