Dell S2719DGF - I don't think G-SYNC CM is working...

[besweeet]

Posts across the web claim that the Dell S2719DGF works well with the new G-SYNC Compatible Mode. I'm seeing no evidence of that. Basically, the screen tearing is as bad with G-SYNC on as with G-SYNC off, regardless of FPS caps...

The monitor is set to 155Hz. My test game is Overwatch. I can exceed 155FPS with no issues. GPU driver version is 419.35 (installed after DDU with networking disabled). CPU is the i7-2600K (4.5GHz). GPU is the GTX 1060 (6GB).

If I use the in-game FPS limiter to 152FPS with G-SYNC Compatible Mode enabled, I still see screen tearing (image)... Of course, that's just a still, but even at 152FPS~, it's noticeable. If I disable FreeSync in my monitor, the tearing just as bad though input lag seems decreased (could be placebo...).

For fun, I capped OW to 60FPS with both G-SYNC Compatible Mode AND the in-game v-sync option enabled and the game visually appears like it's running at 30FPS...

If I enable v-sync in NVCP while G-SYNC is enabled, tearing is obviously gone. I also tried v-sync on + G-SYNC off and the tearing was still gone and the input lag felt the same as with both options on. So, what is the point of G-SYNC?

Something clearly isn't right... Is it the monitor? Or is G-SYNC w/FreeSync mode still experimental?

[jLLL]

You are supposed to use G-SYNC with Vsync on in NVCP. Otherwise you get tearing when you get closer to your refresh rate. The closer you get to your refresh rate, the more likely it is that a frame is rendered faster than your refresh cycle.
GSYNC delays the refresh of the screen in case that the new image was rendered too slow. If the new image was rendered faster than your refresh cycle then the buffer will be changed immediatly and therefore tearing will occur.
Using Vsync fixes this, as it delays too fast rendered frames to keep them in sync with your refresh rate.

[besweeet]

If that's how it's supposed to be used, why doesn't NVIDIA turn v-sync on once G-SYNC is enabled?

I still don't understand what the point of keeping G-SYNC on is when v-sync is the feature that's solves for tearing... Input lag with either configuration is identical.

[jorimt]

Posts across the web claim that the Dell S2719DGF works well with the new G-SYNC Compatible Mode.

Your monitor model is not currently on the official "G-SYNC Compatible" list, so that may (or may not) be a factor here.

I will also note that G-SYNC monitors contain an actual hardware module, and G-SYNC Compatible FreeSync monitors contain no hardware module and instead rely entirely on software, so there can be differences in implementation and functionality between the two methods.

The monitor is set to 155Hz.

Have you tried without the overclock? It's possible FreeSync mode doesn't function when overclocked. Also, just to get it out of the way, you are using DisplayPort, not HDMI, correct? Because G-SYNC Compatible only supports the former.

Once the above is answered, I have some further steps to help you troubleshoot, if necessary.

Something clearly isn't right... Is it the monitor? Or is G-SYNC w/FreeSync mode still experimental?

"G-SYNC Compatible" functionality on FreeSync monitors is indeed still early, and should improve as time goes by; it certainly isn't as mature or comprehensive as an actual G-SYNC module.

[besweeet]

Have you tried without the overclock? It's possible FreeSync mode doesn't function when overclocked. Also, just to get it out of the way, you are using DisplayPort, not HDMI, correct? Because G-SYNC Compatible only supports the former.

Yes; I tried with the overclock disabled (so 144Hz only and with a 141FPS / 142FPS in-game cap) and with a VESA-certified DisplayPort cable.

[jorimt]

If that's how it's supposed to be used, why doesn't NVIDIA turn v-sync on once G-SYNC is enabled?

I still don't understand what the point of keeping G-SYNC on is when v-sync is the feature that's solves for tearing... Input lag with either configuration is identical.

You obviously didn't read much of my article, because I answered all of that in detail throughout (with input lag tests/graphs to boot).

However, If you don't want to read the entire thing, I have some aggregated answers in my Closing FAQ here:
https://www.blurbusters.com/gsync/gsync ... ttings/15/

Yes; I tried with the overclock disabled (so 144Hz only and with a 141FPS / 142FPS in-game cap) and with a VESA-certified DisplayPort cable.

Okay good, for troubleshooting purposes, keep it at 144Hz for now. And we've already established you are also enabling FreeSync from your monitor OSD.

So to confirm, you:

- Enabled the FreeSync option via your monitor OSD
- Disabled the overclock via your monitor OSD, and are now at 144Hz
- Followed these steps to enable G-SYNC Compatible on an unofficially supported monitor

Once the above is confirmed, I took a look at your monitor's manual, and it appears you have another section in your monitor OSD called "Game Enhance Mode."

Please set this to "Frame Rate." I don't own that monitor, so I can't be sure, but that should enable an FPS overlay that will show you your refresh rate fluctuating in real-time in FreeSync/G-SYNC Compatible mode when FPS is within the VRR range.

Let me know if that's the case, and we can continue troubleshooting...

[jLLL]

If that's how it's supposed to be used, why doesn't NVIDIA turn v-sync on once G-SYNC is enabled?

I still don't understand what the point of keeping G-SYNC on is when v-sync is the feature that's solves for tearing... Input lag with either configuration is identical.

In the early days of GSYNC this was the case, but it was changed.
GSYNC syncs all framerates with the monitor, but for Vsync you need to consistently have a framerate equal to your refresh rate, because the monitor is constantly refreshed. In case of GSYNC a refresh cycle of the monitor can be delayed, if the new frame is not completed.
Getting fewer frames with Vsync will therefore create stutter und Vsync will have higher input lag, because if a frame was rendered too slow, then you need to wait at least one complete refresh cycle until the frame can be displayed on the monitor, which will give you input lag. GSYNC will delay the next refresh in this case and keep a static image on the monitor (instead of a refreshing one) and once the new frame is rendered completely, GSYNC will immediately start the new refresh cycle, instead of waiting for the next one in a fixed interval.

[besweeet]

You obviously didn't read much of my article, because I answered all of that in detail throughout (with input lag tests/graphs to boot).

However, If you don't want to read the entire thing, I have some aggregated answers in my Closing FAQ here:
https://www.blurbusters.com/gsync/gsync ... ttings/15/

I read the pages - including the FAQ - extensively yesterday but came away with more questions than answers. I still did not spot an answer in regard to G-SYNC off + v-sync on. Both experiences (G-SYNC off + v-sync on vs. G-SYNC on vs. v-sync on) seemed exactly the same.

Will follow-up with 144Hz testing later today.

[jorimt]

I read the pages - including the FAQ - extensively yesterday but came away with more questions than answers. I still did not spot an answer in regard to G-SYNC off + v-sync on.

Great, good to know you read the article.

Both experiences (G-SYNC off + v-sync on vs. G-SYNC on vs. v-sync on) seemed exactly the same.

That means one of two things:

1. G-SYNC Compatible currently isn't working on your setup (the amount of tearing in your initial image shows this is the most likely).
2. And/or you personally can't distinguish the difference in input lag between the two scenarios (the difference in input lag at 144Hz with an appropriate FPS limit below the refresh rate [with sustained FPS; e.g. 141 FPS @144Hz] between the two is only up to 6.9ms [1 frame], after all).

We should find out which it is in your follow up tests.

[besweeet]

Okay good, for troubleshooting purposes, keep it at 144Hz for now. And we've already established you are also enabling FreeSync from your monitor OSD.

So to confirm, you:

- Enabled the FreeSync option via your monitor OSD
- Disabled the overclock via your monitor OSD, and are now at 144Hz
- Followed these steps to enable G-SYNC Compatible on an unofficially supported monitor

Once the above is confirmed, I took a look at your monitor's manual, and it appears you have another section in your monitor OSD called "Game Enhance Mode."

Please set this to "Frame Rate." I don't own that monitor, so I can't be sure, but that should enable an FPS overlay that will show you your refresh rate fluctuating in real-time in FreeSync/G-SYNC Compatible mode when FPS is within the VRR range.

Let me know if that's the case, and we can continue troubleshooting...

Confirming the latest settings:

• Disabled the overclock (back to 144Hz)
• Enabled the refresh rate overlay via OSD
• Enabled G-SYNC
• Ensured in-game and NVCP v-sync options are disabled (for now)
• In-game FPS cap is set to 141FPS

Still, there's screen tearing. The refresh rate overlay - even when staring at the sky (so a constant 141FPS) - fluctuates wildly between 120Hz~ and 144Hz. (With G-SYNC off, the overlay remains a constant 144Hz, which I guess is to be expected.)