From Nvidia drivers notes. Is better have off Sli for the moment.
Windows 8.1 Issues
 [SLI, Batman: Arkham Knights] With a 4K display, a TDR occurs after the in-game
resolution is toggled and the application is exited. 
 [SLI, Batman: Arkham Knights] Heavy flickering occurs in game after Alt+Tab if SLI is
 [SLI, Batman: Arkham Knights] Severe stuttering seen, especially in indoor scenes,
when the game is running at 4K resolution and NVIDIA Gameworks settings are
turned on. 
 [SLI, Batman: Arkham Knights] Random flickering occurs in the game if SLI is
 [GM206, SLI, Batman: Arkham Knights] Stuttering occurs and performance drops
after shadow quality settings are toggled. 
 [GK180, SLI, Batman: Arkham Knights] When SLI is enabled, a crash points to
ntdll.dll shortly after the game is exited.