Blur Busters Forums

Who you gonna call? The Blur Busters! For Everything Better Than 60Hz™ Skip to content

minor tearing with G-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.

minor tearing with G-Sync

Postby PrejudgedMax » 15 Jun 2017, 16:37

Hi,
So, I've read the articles on G-Sync 101 (Introduction & Range) and am aware of the issues concerning framecaps too close to the refreshrate with G-Sync on and V-Sync off.

However, I can still sometimes see some minor tearing on the bottom half of my screen, even when capping significantly lower than the monitor rate (e.g. 80 fps cap vs. 144 Hz monitor rate) and having both G-Sync and V-Sync enabled.

It is particularly noticeable in Battlefield 1 and to a lesser extent in Witcher 3 (both using in-game capping). It seems to be mostly the case however when there is a lot going on or many assets being loaded in quickly. For example, when walking around in Witcher 3, I can't see any tearing at all, but when sprinting I do see some minor tearing now and again in the bottom of the screen (although you can only notice it when you really focus). When sprinting and looking at the sky, I can't see any tearing either, consistent with there being fewer assets.

Is this all indeed due to frametime spikes and thus unavoidable with GSync? In other words: do we have to allow for some tearing (however small) unless we only use VSync and just delay the whole frame?

Many thanks for any responses and with regards,
PM

---
Monitor: ACER PREDATOR XB271HU
GPU: GTX 1080
PrejudgedMax
 
Posts: 3
Joined: 15 Jun 2017, 16:17

Re: minor tearing with G-Sync

Postby RealNC » 15 Jun 2017, 17:43

AFAIK, this shouldn't ever happen. Are you really sure vsync is enabled in the nvidia panel and not overwritten in a game-specific profile? Or maybe there's some tweak you did in Inspector and forgot about it?
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.
User avatar
RealNC
 
Posts: 1248
Joined: 24 Dec 2013, 18:32

Re: minor tearing with G-Sync

Postby PrejudgedMax » 16 Jun 2017, 05:27

RealNC wrote:AFAIK, this shouldn't ever happen. Are you really sure vsync is enabled in the nvidia panel and not overwritten in a game-specific profile? Or maybe there's some tweak you did in Inspector and forgot about it?


Okay, so I've done some more tests and it does not appear that it's actually tearing that I'm seeing. Only fast-changing areas are affected and not static ones (e.g. the character model). So maybe I'm just seeing some normal minor asset/texture streaming? Would that be consistent?

On an unrelated note, do I still need to enable VSync with Gsync when not in the upper frame range or would it not make a difference? For example, when playing at +/- 80 FPS with the monitor framerate set to 144 or 120? And, also, is there a difference between enabling VSync in the control panel or simply in-game?
PrejudgedMax
 
Posts: 3
Joined: 15 Jun 2017, 16:17

Re: minor tearing with G-Sync

Postby RealNC » 16 Jun 2017, 06:31

PrejudgedMax wrote:Okay, so I've done some more tests and it does not appear that it's actually tearing that I'm seeing. Only fast-changing areas are affected and not static ones (e.g. the character model). So maybe I'm just seeing some normal minor asset/texture streaming? Would that be consistent?

I don't know. Could be. One way to tell for sure is to disable g-sync for a while and play with stand-alone vsync. If you still see the issue (whatever it is), then it's not related to g-sync.

On an unrelated note, do I still need to enable VSync with Gsync when not in the upper frame range or would it not make a difference? For example, when playing at +/- 80 FPS with the monitor framerate set to 144 or 120?

Sometimes there's huge frame time spikes, or single frames that arrive too fast. This results in very short-lived tearing. One game I see this all the time is Deus Ex MD. A 75FPS cap on 144Hz still gives tearing that lasts for very short periods of time. During a camera pan for example, a tear line "flashes" in very shortly from time to time.

Since keeping vsync enabled in the control panel doesn't hurt anything, and gets rid of this issue, there's no reason to disable it. In other words, if there's nothing to gain by disabling vsync, then why disable it?

And, also, is there a difference between enabling VSync in the control panel or simply in-game?

Yes, sometimes there's a huge difference. But only sometimes. Often, there's none. In the cases where there's a difference you can see bad frame pacing. One example is Fallout 4. If you don't disable in-game vsync (through the ini file), the game applies 60Hz frame pacing techniques on top of g-sync, giving severe micro-stutter.

Other games will force triple-buffered vsync (not every game has an option to switch between double-buffered vs triple-buffered vsync.) G-Sync does not benefit from triple buffering. It only increases input lag (slightly) without any benefit whatsoever.

And in general, enabling in-game vsync could result in other internal changes (that we know nothing about) to the game's engine that are supposed to make it work with vsync. Those changes might not have a negative effect with g-sync, or they might. We have no idea.

When using g-sync, it's best if the game thinks it runs without v-sync. Because in fact that's what's actually happening. G-Sync really behaves like vsync off. Disabling in-game v-sync is the best way to ensure that the game does not assume vsync is active. G-Sync really is intended to behave like v-sync off from the game's perspective, so that's the best setting.
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.
User avatar
RealNC
 
Posts: 1248
Joined: 24 Dec 2013, 18:32

Re: minor tearing with G-Sync

Postby PrejudgedMax » 16 Jun 2017, 09:25

Okay, many thanks for all the useful information!!
PrejudgedMax
 
Posts: 3
Joined: 15 Jun 2017, 16:17


Return to G-SYNC

Who is online

Users browsing this forum: No registered users and 4 guests