No Question anymore, but a solution if anybody ever comes across the same problem:
I'm using a Magewell Capture card which runs perfectly fine under OSX, but when i connected it to a Windows Laptop the Video (the preview in OBS, and also in other software) was lagging / stuttering and just looked like low FPS.
It kinda looked like there is a USB Bandwidth problem.
After several hours of looking in the direction of a USB Bandwidth problem i stumbled across posts that address a problem with a windows component that Microsoft changed in 2016 and was thus able to find a solution in another forum that somebody posted:
This also fixed my problem, the Video is smooth now. Maybe it can save some other persons the time that i had to spend to find this solution if you find it here.
I'm using a Magewell Capture card which runs perfectly fine under OSX, but when i connected it to a Windows Laptop the Video (the preview in OBS, and also in other software) was lagging / stuttering and just looked like low FPS.
It kinda looked like there is a USB Bandwidth problem.
After several hours of looking in the direction of a USB Bandwidth problem i stumbled across posts that address a problem with a windows component that Microsoft changed in 2016 and was thus able to find a solution in another forum that somebody posted:
This should restore pre-Windows 10 Anniversary Update behavior and unblock webcams experiencing the freezing-after-few-seconds issue:
Try opening up HKLM\SOFTWARE\WOW6432Node\Microsoft\Windows Media Foundation\Platform and add a DWORD with name EnableFrameServerMode. Set its value to 0 and try again. For 64-bit apps (e.g. UWP Skype), use the same path above, minus WOW6432Node.
This also fixed my problem, the Video is smooth now. Maybe it can save some other persons the time that i had to spend to find this solution if you find it here.