For a couple weeks now I've noticed Firefox seems to run slower after about an hour. I noticed its memory usage starts around 400Mb and jumps to around and over 2GB within an hour. I have 8GB of ram currently, and am usually using 35-45% without FF running. I'm not tab-happy; I usually have between 3-7 tabs open at most. I only have 4 add-ons. I do like to watch videos, and I'd say the more YouTube or Twitch I'm watching, the quicker this happens, but 2GB? I've tried turning on/off recommended settings/hardware acceleration. about: memory will reduce about 200Mb, but of course it continues to climb. The only real 'fix' seems to be restarting it regularly.