Firefox has been lagging for me for awhile, I cant really remember when it started. It gets much worse when I have youtube videos/twitch.tv/many other video streaming sites, as well as when I open a lot of tabs. None of this seems to be a problem in chrome (I really would prefer to stay with firefox). Also, when im watching twitch/youtube it seems to lag much much less when I have it in fullscreen (this is nice, though I dont always want fullscreen, as I like having it run off to the side where I can be doing other things at the same time). It's also very choppy when switching applications. When i open a new tab, generally the little circle blue loading thing at the top is visibly lagging. The page takes forever to open (to the new tab page, i have it set to about:newtab or whatever it is). Then the typing is delayed and choppy. Scrolling is choppy as well. I've seen many support threads about this, but none of the posted solutions have worked. Here is what i've tried so far: - Disabling hardware acceleration (both in firefox, and adobe flash settings). - Clean install - Deleting profiles in %appdata%/mozilla/firefox - Enabling HTML5 in youtube - Setting process priority in task manager - Setting affinity in task manager (removing core 1) - (tried both of the above with both firefox and flashplayerplugin) - Restarting my computer - Disabling extensions (i only have 3 of them, tried disabling all of them) - Running the same stuff in a different browser (this did work fine in chrome) I have also monitored my cpu usage and RAM usage in task manager, and it's generally around 50% CPU and 65% RAM (I am running a lot of other stuff at the same time, and yes, i was running this stuff when i tried chrome). I have 16 GB RAM quad core 3.8 AMD processor 256 GB SSD 1 TB HDD NVIDIA 550 Ti boost graphics I would really like to fix this, as I love firefox, and hate lag. Thanks for any help you can provide!