coballes19 wrote: ↑04 Aug 2021, 06:42
coballes19 wrote: ↑04 Aug 2021, 02:22
Even on the very same monitor, like MAG251RX or VG279Q, its
360hz+60fps is nowhere as smooth as its own 60hz+60fps, all perceived blur taken into account.
I mean their respective highest refresh rate, like 240hz+60fps and 144hz+60fps, is not as smooth as their own 60hz+60fps.
If the frames are perfectly frame paced, then it will look similarly smooth.
Two reasons:
(A) Stutter from minor framepacing issues
But the finer Hz means 60fps frames can jitter more easily over 4.2ms granularities (1/240sec at 240Hz) than over 16.7ms granularities (1/60sec).
(B) Stutter made more visible from reduced motion blur of faster pixel response
In addition faster pixel response of high-Hz can reduce blur enough to make stutter edge vibration more visible above your flicker fusion threshold (the blur-to-stutter continuum, ala VRR ramping --
www.testufo.com/vrr -- where object edges during low framerates vibrate like a slow guitar string -- and goes blurry at high frame rates much like a fast guitar string. Slow GtG will lower this threshold and fast GtG will raise this threshold. The average human flicker fusion threshold is approximately 70 Hz but it can shift upwards and downwards from the multiple variables (such as LCD GtG). Slow LCD GtG pushes this threshold to below 60 Hz, which is why 60 Hz often looks so smooth on slow 60Hz LCDs.
This is also why things also stutter more visibly on a 60Hz OLED than on a 60Hz LCD, because faster GtG makes the flicker of edge-vibrations of stutter more visible (higher flicker fusion threshold).
To help fix (A), enable VRR for your 60fps content, and then use a millisecond precision framerate capper such as RTSS to force the 60fps framepacing to be smooth.
Or just simply temporarily switch your high-Hz monitor to 60 Hz. Problem solved especially if you use custom Quick Frame Transport (QFT) timings data for a low-latency fixed-Hz mode, if necessary.