I upgraded to firefox 57 yesterday and noticed that I had a lot of microstutters when playing games while having firefox run in the background. Upon closer inspection I noticed that firefox was using nearly 4gb of vram. Most of it in one of the processes. At the time of the attached screenshot i was not watching or buffering any videos. I had around 30 tabs open (only around 20 of which were actually loaded) but still 4gb is quite excessive in my opinion. I already tried a refresh but it is still eating the same amount of memory.