G-Sync not in Sync

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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fejerm
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Joined: 09 Jun 2016, 07:02

G-Sync not in Sync

Post by fejerm » 17 Jun 2016, 07:37

Hey all!
I have a Clevo P775DM1-G with a G-Sync enabled LP173WF4-SPF1 screen and NVidia Geforce GTX980 VGA.

G-Sync definitely works during games, since without G-Sync I see stuttering if the FPS drops below 75 (that is the default screen refresh rate).

However if the FPS drops below 50, I am starting to see microstutter on the edges of textures...but maybe microstutter is not the best word. It feels similar as to when I am watching a movie on TV set to 24 hz Refresh rate...the movie is much smoother compared to 60 Hz (no judder/stuttering), however sometimes when the camera is moving, I can see a small jitter/stutter on the edges.

I have tested NVidia Pendulum Demo and have noticed the same there, if the FPS was in the 40s, the movement had some very minor microstuttering. I have also saw that the "Animation FPS" and "Smoothed FPS" were not in sync, the Smoothed FPS was always ~1 sec behind catching up to the Animation FPS.

is this normal for G-Sync, meaning if the FPS is in the 40s, then microstutter during movement is to be considered as "working as intended" ?

Sparky
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Joined: 15 Jan 2014, 02:29

Re: G-Sync not in Sync

Post by Sparky » 17 Jun 2016, 08:44

Well, laptop g-sync isn't the same implementation as desktop g-sync, so I'm not too familiar with the technical details, the lack of a g-sync module does limit some of the engineering options though. Do you know the minimum refresh rate of the monitor?

It's possible the VRR window is too small for frame doubling, and your instantaneous framerate is dropping below the VRR window. Or it may just be some of the new frames are finishing during the re-scan, so they're delayed a bit. In any case, a 75hz max refresh rate puts some significant restrictions on any VRR implementation. The best option is an in-game framerate cap to keep you inside the VRR window, while reducing settings to maintain that framerate. It's still a lot better than a fixed refresh monitor, where you don't have an option that eliminates all 3 of judder, tearing, and input lag.

fejerm
Posts: 6
Joined: 09 Jun 2016, 07:02

Re: G-Sync not in Sync

Post by fejerm » 18 Jun 2016, 02:14

The lowest refresh rate selectable by default is 75Hz.

However the lowest I was able to go with custom resolution in the NVidia Control Panel was 18 Hz, however with this refresh rate the screen was dropping out the signal and had really bad vibrating.

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lexlazootin
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Joined: 16 Dec 2014, 02:57

Re: G-Sync not in Sync

Post by lexlazootin » 18 Jun 2016, 03:07

>18 Hz

that's not safe man, don't do that.

fejerm
Posts: 6
Joined: 09 Jun 2016, 07:02

Re: G-Sync not in Sync

Post by fejerm » 18 Jun 2016, 18:02

Sorry for the stupid.question, but too low.refresh rate can also damage the screen?

While testing each custom refresh rate.was.only active for a few seconds...any chance that the screen got damaged?

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