Most noticeable in Grand Theft Auto V and DiRT Rally.
DiRT Rally forum post, loads of users with same problem: Bug Report: Visual/Pixelated Bug on trees and other objects. :: DiRT Rally Tech Support
You'll need to open these images at 100% zoom to see the problem.
See the netting in the distance: http://i.imgur.com/hfDZir6.jpg
See the bushes and trees: http://i.imgur.com/hgI6fny.jpg
Not as bad but the bushes are wrong: http://i.imgur.com/izOUiC6.jpg
Only AMD uses are reporting this problem, even ones with brand new 390's, looks like some sort of driver bug.