The firefox on my laptop (archlinux) used to be fast and responsive, but it got laggy some time ago. Every UI part seems to lag and be choppy. YouTube videos are unwatchable, scrolling is laggy as well as writing this text. I already tried a new profile and disabled/reenabled hardware acceleration, but there was no improvement. The cpu usage and memory usage is low. Maybe the reason for this problem is the built in combination of Intel and NVidia GPUs (Optimus), but it used to work well. Any help is appriciated because Firefox is unusable this way.