Tearing: G-Sync or V-Sync?

[wanderer]

Hello everyone,

Trying to setup the excellent FS-UAE again. I use a "G-Sync compatible" 144Hz 1080 monitor which is tested and working fine in this mode (in full-screen, since windowed might have issues). Old W10 PC, GTX 1050 Ti, FS-UAE 3.1.68.

FS-UAE tests (simply moving around in Alien Breed '92):

1. 144Hz, G-Sync compatible mode: smooth scrolling but there's an amount of tearing
2. 100Hz, G-Sync off, V-Sync on: all good, no tearing
3. 100Hz, G-Sync on, V-Sync on: mediocre results
4. 100Hz, G-Sync off, V-Sync off: mediocre results
5. 144HZ, G-Sync on, V-Sync on: similar to (1)

Do these look expected and normal? I thought G-Sync was the better solution, even in its AMD Freesync / G-Sync "compatible" incarnation?

Tried playing around with some Video/Advanced Video settings but couldn't improve (1) above, so reverted to the defaults. Any suggestions to improve G-Sync compatible mode, or there's nothing to do and stick with (2)?

Thank you

[RuySan]

I just set my monitor (which doesn't have gsync)to 50hZ...and it's silky smooth with vsync

[wanderer]

Thanks. After several tests with various games, it looks like V-Sync is indeed the better option. Perhaps the "G-Sync compatible" implementation is not good enough on my monitor, or G-Sync is not ideal for this situation. When background graphics are moving, there's tearing. The larger the graphic elements, the more visible it becomes.

About V-Sync: 100Hz performs great. If I set the monitor to 50Hz, it performs badly.

[dreadnought]

V-Sync adds input lag, so if you have a VRR capable monitor it's worth researching this a bit further and making it work. I'm pretty sure it's possible, but it's been some time since I have used it so don't remember the details. Search this forum, there are threads which discuss it in-depth.

[Retro-Nerd]

1. 144Hz, G-Sync compatible mode: smooth scrolling but there's an amount of tearing

The "G-Sync compatible" monitors lacks the native G-Sync hardware module from much more expensive displays. My Dell monitor is G-Sync compatible too, but it's mainly a Freesync monitor and works fine in that mode with everthing. Mandatory for that seems to be native monitor resolution and hightest settable refreshrate (my my case 165Hz). I don't use Vsync at all.

[wanderer]

@dreadnought: Thanks for telling me to persevere. Also looked in EAB but I found this nice guide: G-SYNC 101: Optimal G-SYNC Settings. Things improved in G-Sync/144Hz mode, although it's still not silky-smooth as V-Sync/100Hz. I made these changes specifically for fs-uae.exe in the Nvidia 3D settings:

Low Latency Mode: Ultra
Vertical sync: On
Max Frame Rate: 140 (they say it's better for this FPS limiting to be done "in-game" but I don't know if/how it can be done if FS-UAE).

@Retro-Nerd: Yes, "G-Sync compatible mode" is meant for Nvidia cards on AMD FreeSync monitors which is my case, too (ViewSonic XG2405). FreeSync is a bit less effective than G-Sync, but I think it's enough for Amiga gaming (as proven by your monitor).

[wanderer]

I think this might be related with this old system being forced into PCI-e 1.1 mode. I don't remember having "G-Sync compatible" issues on an equally old system with a weaker CPU but PCI-e 2.0 mode (same video card and monitor).

[dreadnought]

http://eab.abime.net/showthread.php?t=105802
http://eab.abime.net/showthread.php?t=105716

So as you can see in these threads it's entirely possible. I don't have the same GPU anymore so can't check it again but it just has to work. Btw, you are connecting via DP right?

[wanderer]

Yes, DisplayPort. I will fiddle some more with settings and possibly another Nvidia driver, but it's mostly ok as it is now. I think this is probably caused by my very old hardware.

[dreadnought]

Your hardware is not old at all, I mean, not old in a way it should matter. It is indeed probably something with the settings, because there are several layers of them which might affect the same thing.

[wanderer]

Glad to report that after an Nvidia driver uninstall/reinstall (using Display Driver Uninstaller), it now works perfectly with no special settings or changes. It clearly wasn't before since the monitor OSD menu always reported 144Hz, but now I see it keeps changing to 98, 102, 104Hz etc. while gaming.

A minor problem now is that the monitor goes to full brightness/contrast (thus resetting my lower, changed settings) but I can live with that.

update: It didn't last long. Again, it seems it's not getting enabled at all. Back to the drawing board.

[wanderer]

I think I finally nailed it. I have a second monitor (always disabled in these tests). There's a "Enable settings for the selected display model" tick in the Nvidia driver. Enabling this, makes G-Sync Compatible mode work consistently. Btw my monitor is not officially validated by Nvidia as compatible. It would be nice, but it is not mandatory.

As for the full brightness: pressing Ctrl-Win-Shift-B initializes the display driver and the monitor brightness settings will instantly go into effect again. Thanks all for the suggestions.

[FrodeSolheim]

Good to hear

I'm using G-Sync on Linux myself, and it is fantastic for emulation! However, I too had problems with multiple monitors. For some reason, when both my monitors are connected, I get short bursts of severe stuttering every few seconds. It does not help to disable the other monitor in nvidia settings, I have to disconnect the cable to the second monitor. Then everything works great.

[cybermat]

I have just one LG gaming monitor connected (Gsync compatible) with a 1050 video card. I prefer playing emulation on this enviroment, because VRR is the solution for input lag and the right refresh rate.
I have a Trinitron on the left and this LG on the right, sometimes i put the same game and i compare it using different CRT shaders and then i play 5 minutes each one.
CRT is always the original solution, but sooner or later we should say goodbye to it, with recent implementation, LCD quality and good Crt shaders, we can go on with good results.

[dreadnought]

Originally Posted by cybermat

CRT is always the original solution, but sooner or later we should say goodbye to it, with recent implementation, LCD quality and good Crt shaders, we can go on with good results.

I don't plan on doing that anytime soon, because LCDs are still not good enough (for me). Shaders are impressive but they are still only an interpretation, on a different tech, and take a lot of fiddling with to get right. There's also an issue of motion blur, which is unacceptable on most LCDs.

So, while it's certainly possible to achieve "good" results (especially compared to how things were 10 years ago), I can get a perfect one by just plugging my OG HW or MiSTer into the real thing.