I bought new parts for my comp some months ago. The upgrades doubled my FPS (from 40 to 80, on average) and I was happy. Then Legion was launched, and I've had some difficulties getting the FPS to stabilise at 60. Some of that is linked to the fact that a LOT more players are now on the screen (how peaceful my Garrison was!), but my FPS has been stuttering for days now. I decided to look at apps running in the background (this was after updating graphic drivers etc). I had a LOT running, like Chrome (don't remember I gave that permission), and I cut it down quite brutally. The results were very positive: I now have 60 FPS stabilised, no ability lag and no stuttering. I have no idea why this is so. My comp has been running all these apps in the background for years now, without problems. But it seems to me that Legion is more demanding (or less optimised) than WoD. It also seems like some of the apps are more demanding. Updates for Win 10 could also be part of the explanation.