first If you use SLI . you need to remove your secondary vga out. not just disable it
second go to setting Nvidia and click default button
third disable volummatic fog and screen space reflex at visual .
and last Disable HT in your mainboard
atm I play at 4K @60 fps with no stutter or micro stutter.
only issue is got is fps drop when monster heavy spawn . and its bcouz its not SLI
I hope it will help :>