Comment 4 for bug 1387558

I have done interesting experiment, I changed rotation for external monitor to "Normal" instead of "Counterclockwise" and performance is horrible:
137 frames in 5.0 seconds = 27.347 FPS
126 frames in 5.0 seconds = 25.135 FPS
135 frames in 5.0 seconds = 26.809 FPS
145 frames in 5.0 seconds = 28.856 FPS
186 frames in 5.0 seconds = 37.178 FPS
299 frames in 5.0 seconds = 59.658 FPS
299 frames in 5.0 seconds = 59.661 FPS

Again when I change it back to "Counterclockwise" performance is back and good.