[Thread Superseded] G-Sync 101 w/Chart (WIP)

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.
drmcninja
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Re: G-Sync 101 w/Chart (WIP)

Post by drmcninja » 31 May 2017, 16:08

Is there anything worse about using Overwatch's in-game V-Sync setting instead of NVCP? It seem to work the same.

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Re: G-Sync 101 w/Chart (WIP)

Post by drmcninja » 31 May 2017, 16:13

Btw, in your article are you going to have comparisons of input lag with:

Fast-Sync with FPS limited to Refresh Rate

Fast-Sync with FPS uncapped (e.g, 300)

V-Sync with FPS limited to -1 or -2 below Refresh Rate (without G-Sync)

My friends with 60Hz monitors have been wondering which is better to use, but right now I've told them to stick with V-Sync @ 59fps because Fast-Sync isn't working in Overwatch yet. I would think, if it were available, Fast-Sync would be better for 60Hz and ~100fps average that they get. I've got another friend who, like me, is at V-Sync 119fps @ 120Hz, but isn't sure whether going to Fast-Sync (once it is working) would be better with less input lag.

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Re: G-Sync 101 w/Chart (WIP)

Post by Sparky » 31 May 2017, 16:30

The latency added by fast sync(or vsync when capped below refresh rate) is half a frame of latency or half a refresh cycle, on average(whichever is lower). Any single frame can be delayed between 0ms and 1/framerate, so it averages to 1/2 a frame. This is in addition to any lag added by the framerate cap itself(1 frame for RTSS, almost nothing for an in game cap).

Basically, the delay you're adding is the difference in time between the tear closest to the bottom of the screen and the start of the next refresh cycle.

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Re: G-Sync 101 w/Chart (WIP)

Post by jorimt » 31 May 2017, 17:15

drmcninja wrote:Is there anything worse about using Overwatch's in-game V-Sync setting instead of NVCP? It seem to work the same.
Nvidia Control Panel V-SYNC is generally safer to use, as it guarantees no extra frame pacing behaviors or other quirks are caused by the specific game engine's implementation, if any are to be had.
drmcninja wrote:Btw, in your article are you going to have comparisons of input lag with:

Fast-Sync with FPS limited to Refresh Rate

Fast-Sync with FPS uncapped (e.g, 300)

V-Sync with FPS limited to -1 or -2 below Refresh Rate (without G-Sync)
Yes, yes, and yes (though since they're being compared directly to G-SYNC, both scenario 1 and 3 have -2 FPS limits).
drmcninja wrote:My friends with 60Hz monitors have been wondering which is better to use, but right now I've told them to stick with V-Sync @ 59fps because Fast-Sync isn't working in Overwatch yet. I would think, if it were available, Fast-Sync would be better for 60Hz and ~100fps average that they get. I've got another friend who, like me, is at V-Sync 119fps @ 120Hz, but isn't sure whether going to Fast-Sync (once it is working) would be better with less input lag.
V-SYNC + 119 FPS limit at 120Hz is roughly the same as Fast Sync + 300 FPS limit at 120Hz, at least input latency-wise. In my testing, you'd have to have framerates up to 5x above 120Hz (600 FPS) with Fast Sync to match G-SYNC input latency levels (about 4-5ms input latency reduction over Fast Sync + 300 FPS) with a 118 FPS limit at 120Hz.
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Re: G-Sync 101 w/Chart (WIP)

Post by kurtextrem » 01 Jun 2017, 01:23

My G-Sync isn't working if I have vsync on + gsync, but fps never goes over 159 fps, or is it?
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Re: G-Sync 101 w/Chart (WIP)

Post by RealNC » 01 Jun 2017, 10:12

kurtextrem wrote:My G-Sync isn't working if I have vsync on + gsync, but fps never goes over 159 fps, or is it?
Can you elaborate? What is your refresh rate?
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Re: G-Sync 101 w/Chart (WIP)

Post by kurtextrem » 01 Jun 2017, 10:16

(Asus PG248Q) 160 Hz and the game I play is Rainbow Six Siege. It is set to 159 Hz and V-Sync off ingame. In NVCP: G-Sync on, V-Sync on. Global profile (and DWM.exe) G-Sync off, V-Sync on.
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Re: G-Sync 101 w/Chart (WIP)

Post by jorimt » 01 Jun 2017, 10:42

@kurtextrem

Are you using an FPS limiter, and if so, which one? If you're refresh rate is 160Hz, you'll want to set an FPS limit about 2-3 below (157-158) to stay in the G-SYNC range at all times. 1 frame below your refresh rate isn't quite enough.
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Re: G-Sync 101 w/Chart (WIP)

Post by kurtextrem » 01 Jun 2017, 10:44

I am not using any frame limiter. That is why I'm asking. I rarely reach > 150 fps anyway, but since I've turned on V-Sync (+ G-Sync) it hits 159 fps sometimes, but never goes over it.
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Re: G-Sync 101 w/Chart (WIP)

Post by RealNC » 01 Jun 2017, 11:01

kurtextrem wrote:I am not using any frame limiter. That is why I'm asking. I rarely reach > 150 fps anyway, but since I've turned on V-Sync (+ G-Sync) it hits 159 fps sometimes, but never goes over it.
Yes, with v-sync enabled, you will never go above 160FPS. (You get 159 because it's truncating the value. It's something like 159.9, but the .9 is cut off.)

For g-sync to work, you need to be at least 2FPS below your refresh rate. So you need to use an FPS limiter. This is explained here:

http://www.blurbusters.com/gsync/gsync101-range/
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