Back when I previewed Sniper: Ghost Warrior 3 I encountered a huge problem where turning around resulted in massive dips in framerate that made the game unplayable. Oddly the only way around the issue was to use a Xbox 360 controller. Skip forward to the full release and the problem is, to my everlasting annoyance, still there, except now at least me and many other Steam users have tracked the source of the problem; the polling rate of the mouse. To solve the problem I've had to turn my polling rate down from 1000Hz to 125Hz or just play with an Xbox controller. Talk about strange.