today i found out something very very good for my condition!

(680gtx sli, 2500k@4ghz, 8gbram)

now my game runs smooth 60fps NO microstuttering no FPS drops anymore

If you have sli and have poor performance you have to do this:

on nvidiainspector TURN OFF AFR2 and set it to default !!! dont turn on!

sli compatibility bits to default (0x00000000)

sli compatibility bits (DX1x) change it to 0x080202F5 (Batman: Arkham City)

change vertical sync to: use 3d application setting

change Number of GPUS to use on SLI rendering mode to SLI_GPU_COUNT_TWO

change NVIDIA predefined number to use on SLI rendering mode on Directx 10 SLI_PREDEFINED_CPU_COUNT_DX10_TWO

change NVidia predefined number of GPUs to use on SLI rendering mode SLI_PREDEFINED_GPU_COUNT_TWO

change Multi-display/mixed-GPU Acceleration mode Single Display performance mode

change Power management mode Prefer Maximum performance

SLI rendering mode must set to Default SLI_RENDERING_MODE_AUTOSELECT

Make sure there is no FRAME RATE LIMITER off

APPLY CHANGES

so now you have sli working, but there could be microstuttering to fix this solution do this:

fallout4.ini and fallout4prefs.ini an your documents c:\

do this also on fallout4_default.ini on X:\Fallout 4\steamapps\common\Fallout 4 and x:\Fallout 4\steamapps\common\Fallout 4\Fallout4 the fallout4prefs.ini

change following things:

iPresentInterval=1 this enables the gameinternal vsync (otherwise you get terrible tearing)

iPresentInterval=1
bTopMostWindow=0
bMaximizeWindow=0
bBorderless=1
bFull Screen=0

iSize H=1080
iSize W=1920

(iSize shoul be your Fullscreen screensize)

this forces your game to open in windowed/borderless mode wich disables the microstuttering

(when looking @ an object and running around it, terrible for eyes but borderless/windowed mode disables this terrifying look)

no my game runs @60fps and looks extremely smooth to me (without ipresentinterval=0, wich disables vsync, my game runs @155-175fps and both of my gpus Bounces up to 100% usage but its too much for the gameengine so set ipresentinterval=1 like i said to get smoothness+maximum fps)

also make sure there is no vsync forced by other programms you are running in background!

i hope this could help everyone even without sli it works good for me