I know this problem has found is share of interest on the internet in the recent years. But I couldn't solve my issue using these answers.
Now I managed to enclose the problem into a few parameters, so maybe I can solve this once and for all.
When connecting to a second screen (HDMI and thunderbolt), there is absolutely no problem with Extend and Duplicate. Works as intended. When Second screen only is chosen however, even the windows explorer stutters with low fps. This issue resolves when using full screen applications.
So I guess the main question is, why my second screen gives 60 FPS on heavy demanding games, but gives 5 FPS on windows explorer, or anything that is not full screen. The first thing comes to mind is the integrated graphics still trying to handle non-full screen applications, but the screen is connected to the dedicated graphics.
System Properties:
MSI Gaming laptop (2016)
Windows 10 Pro (Latest version)
Intel 6700 HQ
Nvidia GTX 1060 (3 GB)
Intel® HD Graphics 530
(Both drivers up to date)
I won't give details of the second screen, because the same behavior happens in all external displays I tried. But I can say that both screens are 1080p and 60 Hz.
Happens with both HDMI and thunderbolt.
