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Hel me how Gsync, vsync and fps cap interact

Posted: 07 Oct 2017, 07:24
by lexebidar
Hey!
I've got AG251FG 240hz gsync this week and I need some help understanging few things.

How does Gsync, Vsync and riva tuner fps cap interact with each other?
At first I thouht that it's best to set fps cap to 238 and vsync to off, so gsync is always engaged smoothing framerate and eliminating tearing. But after reading 101 guide I understand that vsync have to also be forced "on" in control panel?

I do notice little bit of tearing when capped at 238fps in older game. But only at the bottom of the screen. I am testing with older game painkiller because It have easy command to cap framerate.
-At 600fps, gsync 240hz (lol) there is a lot of tearing.
-Cap fps to 238 and tearing is gone. Only little bit left on the bottom of the screen.
-Cap to 200 and all tearing is gone.
-Unlock framerate but engage nvcp vsync and it caps at 239 and all tearing is gone and presumably gsync not engaged anymore?

how should it be used in high fps games and in lower fps games like Witcher3 (which works about 70fps)

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 07 Oct 2017, 07:46
by mello
From what i understand this is how you should do it:
Optimal G-SYNC Settings

Settings tested with a single G-SYNC display on a single desktop GPU system; specific DSR, SLI, and multi-monitor behaviors, as well as laptop G-SYNC implementation, may vary.

Nvidia Control Panel Settings:

- Set up G-SYNC > Enable G-SYNC > Enable G-SYNC for full screen mode.
- Manage 3D settings > Vertical sync > On.

In-game Settings:

- Use “Fullscreen” or “Exclusive Fullscreen” mode (some games do not offer this option, or label borderless windowed as fullscreen).
- Disable all available “Vertical Sync,” “V-SYNC” and “Triple Buffering” options.
- If an in-game or config file FPS limiter is available, and framerate exceeds refresh rate:
Set 3 FPS limit below display’s maximum refresh rate (57 FPS @60Hz, 97 FPS @100Hz, 117 FPS @120Hz, 141 FPS @144Hz, etc).

RTSS Settings:

- If an in-game or config file FPS limiter is not available and framerate exceeds refresh rate:
Set 3 FPS limit below display’s maximum refresh rate (see G-SYNC 101: External FPS Limiters HOWTO).
This is from https://www.blurbusters.com/gsync/gsync101-input-lag/ , "Optimal G-SYNC Settings" section.
So, for all games where you want to use G-SYNC (all games will run below 240 FPS), you need to set a limit of 237 FPS and set V-SYNC ON in NVIDIA panel. There will be no tearing and G-SYNC will be active at all times. If you want to run a game at higher FPS (above 237) then you can do that just by disabling G-SYNC and using V-SYNC OFF.

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 07 Oct 2017, 10:03
by lexebidar
Thanks. That is clear enough!

One thing is that RTSS is going only up to 200fps it seems. Lol they need to up their game to the 240hz standard :D

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 07 Oct 2017, 13:20
by RealNC
I think the latest RTSS beta allows up to 300FPS?

http://www.guru3d.com/news-story/downlo ... ta-18.html

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 07 Oct 2017, 15:15
by lexebidar
yep it does. thanks.

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 12 Oct 2017, 10:59
by Chief Blur Buster
That was a request from me.

RTSS added 300fps because I asked them to, explaining the need for that new limit due to 240 Hz monitors. ;)

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 12 Oct 2017, 11:24
by lexlazootin
a max of 300? or added 300?

Why would they cap it at all?...

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 12 Oct 2017, 13:42
by RealNC
Unwinder once said "to prevent users from entering bogus values and then complaining about it."

:P

It's not really capped though. It's only capped in the UI. In the profile file, you can cap to anything you want.

Re: Hel me how Gsync, vsync and fps cap interact

Posted: 12 Oct 2017, 16:47
by Chief Blur Buster
lexlazootin wrote:a max of 300? or added 300?

Why would they cap it at all?...
I don't know, you can go higher via editing the configuration file.

Either way, it needs to be capped below the refresh rate with GSYNC/FreeSync great low-lag performance.