I recently got an update for my Firefox and after that it has become very slow! What I tried to do: - updated all plugins - disabled all addons - ran Firefox in a safe mode - created a new fresh profile - updated video driver, turned on/off hardware acceleration - changed option layers.offmainthreadcomposition.enabled to "false" It's still slow! As of now, I have a brand new profile without any addons and about 10 tabs opened. There is a noticeable lags when I switch between tabs, open new ones, scroll, and navigate through Firefox menus. Firefox, what's wrong with you? How to make you work right at it was on version 3.x? Some details: I have a dell e6430 laptop, core i5 CPU, 16 GB RAM, 128 SSD, lots of free RAM, almost nothing running in background and consumes CPU.