The composition preview FPS display hovers just over 60FPS but sometimes drops below, so I assume if I go to FPS 60 in Syphon I will actually be getting some frame drops.
EDIT: Just checked with 60FPS on Syphon get this warning pop:
WARNING!: The destination drive or encoding processor wasn't fast enough- try lowering the framerate or resolution, or selecting a faster drive!
Usually bad frame drops are obvious to the eye, but I'd like to know whether there is some way of either scanning a video file to automatically check for frame drops, or of finding out via Resolume or logs or something whether frame drops occurred relative to the Auto FPS setting.
According to Zoltan on this forum posting there is no way (yet) to actually fix the FPS:
Auto change project frame rate to match video clip option
Resolume can't be locked to 30fps currently. The FPS you can set in the composition settings is a maximum.
FPS can dip below that if loads are high.
EDIT: If I set the Composition FPS to 30, it indeed sometimes drops just below 30. BTW This matches the 30FPX dvx resources using for this:Auto FPS setting will use whatever your GPU can do. The cap there is your slowest display you
From Resolume help page: https://resolume.com/support/en/composition
Tip! For super smoooooth playback, you'll want to match the framerate of your composition to the framerate of your content. 25 fps clips will play silky smooth when the comp is set to 25 as well.