this seems to have only happened with a recent update after a few hours open, the laptop's fan starts making noises. previous to a recent re start, I was getting about 50% (exactly) cpu usage after a few hours use (this has been for the past 2 or 3 weeks - 50% cpu use after a few hours of browser open, for 2-3 weeks). yesterday I restarted, process explorer is now showing 80% (80) cpu usage. Task manager shows my cpu almost maxed. something's.....changed in the memory management or something. there has been a software change. noticeable step change about....3 weeks ago till yesterday, 50% cpu use after Ff open for a few hours. today, cpu usage is now 80% after a few hours of brower open I'm on 86.0.1, W7 64bit