The key points are:
These 2 figures dont match - therefore it will stutter at a regular interval.what is your graphics card output refresh rate?
both outputs: 60Hz
what is your SDI input frame rate?
-59.94 (what I am being told)
To reduce the stutter - you must make these figures match - by changing one of them...
what did you find that works?I changed input settings and have found something that works