I have a powerful computer with a GTX980 G1 gaming (OC), but because use QHD resolution (2560x1440) I was not able to play on the UBER setting (after 30 minutes graphics overheated), so set up a HIGH in graphics set-up. It was good, until enter to the city Novigrad. Suddenly game began crash every few or several minutes. So I tried to find a solution to this. I remembered that in the GeForce Experience is the option “optimal setting” so I pressed the button and automatically optimized game and then went to the game. I very surprised as the “optimal settings” of GeForce set a veritable mix settings, partly “High” and partly "Uber". The most interesting that flagship appendix Hairworks was automatically deactivated by Geforce (although I have a top-tier card) and screen play options is in window (not on a full screen, as i had previously set). So I left this settings selected by GeForce Experience, which are higher than previously, but I have put one change to these settings - unlocked V-Sync in game (fps). And the problem has disappeared, do not have any more crashes in game in spite of the fact that I'm now have the higher graphic settings.