How to force Retroarch to run 50 Hz games properly?
Even after setting my monitor to 50Hz on the nvidia control panel, I can see the scrolling not being smooth on Amiga games. I compared to FS-UAE, and the scrolling on Shadow of the Beast feels jerky.
video_refresh_rate = "50"
And then the driver will switch automatically if the rate is available.
You fail because you need to disable windowed full screen mode too (and save core overrides) . Or else it will run on your desktop resolution 
Most monitors do 50/60 and is a matter of drivers allowing it. Some Intel gpu old drivers do, new don’t. Nvidia surely does and I do it on my 1060 and 1070.
Hi ! Eh, you saw my deleted post, ahah 
Maybe I should open a new thread ? Hmm…
Regarding your suggestion : obviously I had already applied it
I actually filed a bugreport here : https://github.com/libretro/libretro-uae/issues/471 Anyone getting butter smooth 50 Hz in RetroArch under Linux ? (amdgpu here)
I’ll open a new thread I guess.
So I made a new thread here : PUAE 50 Hz multiple issues (core override, whdload game vs floppy one)