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Re: [Troubleshoot] Why Vsync had better latency than frame cap with Freesync? [FIXED]
Posted: 10 Aug 2023, 15:07
by Chief Blur Buster
Stizzie wrote: ↑06 Aug 2023, 01:01
I want to make a correction for someone maybe come across this thread because now the title is rendered wrong information (it was at first place, my bad). Vsync is worst latency wise.
I've renamed the topic for you, to reflect this token thread's path to its destiny.
Re: [Troubleshoot] Why Vsync had better latency than frame cap with Freesync? [FIXED]
Posted: 10 Aug 2023, 15:11
by Chief Blur Buster
Stizzie wrote: ↑06 Aug 2023, 01:01
In instances where 60 fps is enough. Can I change the refresh rate to 60hz, essentially manipulate the Vsync cap to 60 ? Does VRR work with every refresh rates in its range or it has to be the native max refresh rate ?
Unless you have a very good reason to do so (e.g. non-VRR content that doesn't work well in VRR), you will always have lower lag with 60fps at max-Hz.
Not all displays refresh all pixels at the same time --
www.blurbusters.com/scanout for high speed videos.
And video cables don't transmit all pixels at the same time. A single frame could take 1/60sec to transmit (60Hz) or 1/144sec to transmit (144Hz)
On a 144Hz VRR display, 60fps would have a scanout latency of 1/144sec, typically both on the cable and on the panel itself (ideally, they're the same). That means a frame will refresh the panel in 1/144sec, even if the refreshes are at an interval of 1/60sec apart.
Lowering your Hz to 60fps will throttle the cable scanout to 1/60sec. Which means 1/60sec for frame transmission from first pixel through last pixel.
Keeping max Hz VRR, will speed up frame transmission (scanout over cable) and refresh (scanout on panel).