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No ghosting when using super fast response time with gsync

Posted: 09 Nov 2019, 13:25
by Jestaz
So i recently turned gsync off (AW2518Hf) to see if i would feel any difference in responsiveness, while playing apex legends. After a few rounds i was browsing a bit and noticed that when scrolling down i had ghosting. When i first set up my monitor i tried out super fast response time and while most people were mentioning that it should be kept on norma, due to massive ghosting, i didn't notice any of that so kept it on super fast (I even did the ghosting test on your site to verify and double checked by doing the same test on my dell S2417dg which had ghosting on everything else but normal).

So since i had ghosting now i set the setting on my monitor to normal again and the ghosting was gone. I remembered not having any ghosting with gsync enabled, so i did some testing.

Turns out that when i have gsync enabled, that i have absolutely no ghosting on super fast response time. How is that possible? Since i only activated gsync in full screen mode, how does it have influence during browsing websites? I seem to be able to run super fast, but only if my gsync is enabled.

If i would decide to keep gsync disabled, would turning back to normal response time make the performance worse than keeping gsync enabled and response time on super fast? I am interested in having the lowest input lag option here.

Re: No ghosting when using super fast response time with gsy

Posted: 09 Nov 2019, 14:03
by Q83Ia7ta
Overdrive algorithm changes when g-sync is enabled afaik.
If u interested in lowest input lag first of all disable g-sync, then cap fps in game, then check v-sync is off everywhere and then try different overdrive values (super fast, normal, etc) and keep most comfortable one. Response time setting has no real impact to input lag. G-sync does more impact to input lag but it's already negligible. Correct me if I'm wrong.

Re: No ghosting when using super fast response time with gsy

Posted: 09 Nov 2019, 14:36
by jorimt
Q83Ia7ta wrote:G-sync does more impact to input lag but it's already negligible. Correct me if I'm wrong.
The only input lag G-SYNC "adds" over V-SYNC is it's lack of tearing.

Re: No ghosting when using super fast response time with gsy

Posted: 10 Nov 2019, 05:51
by RealNC
Overdrive works quite differently when g-sync is engaged. Basically, there's two different overdrive methods in g-sync monitors: Fixed refresh overdrive and variable refresh overdrive. As a result, gsync vs non-gsync can look very different when it comes to ghosting.

Re: No ghosting when using super fast response time with gsy

Posted: 04 Dec 2019, 17:32
by soulhunter0504
RealNC wrote:
10 Nov 2019, 05:51
Overdrive works quite differently when g-sync is engaged. Basically, there's two different overdrive methods in g-sync monitors: Fixed refresh overdrive and variable refresh overdrive. As a result, gsync vs non-gsync can look very different when it comes to ghosting.
Doesn't he have the freesync version without the gsync hardware? Would he still have the variable overdrive with gsync on? How is his ghosting gone when I heard it was a problem on the 2518hf model? I bought one on blackfriday but I was thinking of returning it for a 2518h.

Re: No ghosting when using super fast response time with gsy

Posted: 04 Dec 2019, 17:42
by Chief Blur Buster
soulhunter0504 wrote:
04 Dec 2019, 17:32
Doesn't he have the freesync version without the gsync hardware? Would he still have the variable overdrive with gsync on? How is his ghosting gone when I heard it was a problem on the 2518hf model? I bought one on blackfriday but I was thinking of returning it for a 2518h.
Most FreeSync monitors do not have variable overdrive. Sometimes the fixed overdrive is used in conjunction with VRR, but the problem with that is that you see ghosting/coronas appear/disappear/reappear as the framerate modulates up and down.

<TECHNICAL>

This is because pixel response curve is static, and you’re interrupting different portions of the GtG response curve because of the varying refresh cycle lengths. For 240Hz VRR, 1ms GtG can still take more than 4ms, as seen in the Pixel Response FAQ: Questions about GtG vs MPRT, since it’s a measurement from the 10% point of the curve to the 90% point of the curve. A pixel on an LCD always “fades” from one color to the next at a fixed speed, as seen in high speed videos at www.blurbusters.com/scanout .... If a pixel begins its new refresh cycle (new transition) when it’s only partially transitioned, the human eye can perceive it as a brighter pixel or darker pixel than it should be — a ghosting/corona artifact. So you need to kind of vary the overdrive during the variable frame intervals, to try to keep pixel transitions similarly ghost-free / corona-free at all frame rates.

</TECHNICAL>

Re: No ghosting when using super fast response time with gsy

Posted: 27 Jan 2020, 13:14
by Bamboo
RealNC wrote:
10 Nov 2019, 05:51
Overdrive works quite differently when g-sync is engaged. Basically, there's two different overdrive methods in g-sync monitors: Fixed refresh overdrive and variable refresh overdrive. As a result, gsync vs non-gsync can look very different when it comes to ghosting.
Is the fixed refresh rate overdrive the same if the monitor is set to for example 165hz and then 100hz, or does it change to best fit the set hz?

Re: No ghosting when using super fast response time with gsy

Posted: 01 Feb 2020, 15:02
by ELK
Bamboo wrote:
27 Jan 2020, 13:14
RealNC wrote:
10 Nov 2019, 05:51
Overdrive works quite differently when g-sync is engaged. Basically, there's two different overdrive methods in g-sync monitors: Fixed refresh overdrive and variable refresh overdrive. As a result, gsync vs non-gsync can look very different when it comes to ghosting.
Is the fixed refresh rate overdrive the same if the monitor is set to for example 165hz and then 100hz, or does it change to best fit the set hz?
Good question. If I'm going to play a game with a 100fps cap and gsync will choosing a different refresh rate, say 144 vs 240hz change it's overdrive? Chief said while it's modulating. Does that mean it doesn't matter as long as the fps is stable... I wonder

Re: No ghosting when using super fast response time with gsync

Posted: 01 Feb 2020, 17:40
by Bamboo
ELK wrote:
01 Feb 2020, 15:02
Good question. If I'm going to play a game with a 100fps cap and gsync will choosing a different refresh rate, say 144 vs 240hz change it's overdrive? Chief said while it's modulating. Does that mean it doesn't matter as long as the fps is stable... I wonder
If you have a monitor with Gsync hardware, not Gsync compatible, it's overdrive is variable.
If you cap the game to 100fps with Gsync turned on, the refresh rate won't go over 100hz. But it will follow the games fps if it drops below 100.
And the overdrive will adjust accordingly.

I was hoping @RealNC could explain how overdrive works on a monitor with Gsync hardware and Gsync turned off. Fixed refresh rate.

Re: No ghosting when using super fast response time with gsync

Posted: 02 Feb 2020, 13:29
by RealNC
Bamboo wrote:
01 Feb 2020, 17:40
I was hoping @RealNC could explain how overdrive works on a monitor with Gsync hardware and Gsync turned off. Fixed refresh rate.
Only nvidia knows.