I have something similar and much more severe than that. 8.1 is 5 times better than what I've had. I've noticed that, in my case, it gets to 41 milliseconds. I cannot explain this myself. It happens when the camera gets into a certain position. Just a change of about 40 quants, refresh time goes from around 8 milliseconds to 40. Go back down about 40 quants and it returns to 8.... I'm baffled over it myself.

PS nice scene.

"You level up the fastest and easiest if you do things at your own level and no higher or lower" - useful tip My 2D game - release on Jun 13th; My tutorials