Okay, the results are in! Tested on my Samsung plasma, since the much better pixel response time makes it easier to spot when a change is happening on the screen. Tested with Yoshi’s Island again and filmed in 60 FPS with a Canon EOS 70D.
gl driver: 12 frames
dispmanx: 11 frames
dispmanx + video_hard_sync = true: 11 frames
I’d say the dispmanx driver was rather consistently 1 frame faster, but it’s still close enough that I wouldn’t bet my life on there being any real difference.
Disappointing results, of course. I wonder what I should test next…