Is G-Sync compatible really useful for high refresh displays?

eLPuSHeR · 08 Jun 2021

Hello.

I have got an ASUS G-Sync compatible 27" 165Hz refresh display. I am not very impressed by games running G-Sync compatible mode. Is G-Sync compatible that useful really? Aside from csgo which is quite picky for input lag, most games seem to run smoother by using normal VSYNC.

What do you think?.

eLPuSHeR · 09 Jun 2021

To sum it up this is what I have found so far.

1. G-sync and, I guess AMD's counterpart Freesync don't work beyond display maximum refresh rate. I think they work on a given range, e.g. 40Hz - 144Hz. With most games yielding 250+ fps on 1080 for my GTX1070 card, one must use a frame limiter if available or use vsync in tandem with Gsync.
2. I haven't seen any game with built-in VRR support. And most framecappers don't work properly.
3. I am sensitive and I still perceive certain screen tearing even with Gsync on.
4. I think it's better to have a high-quality screen display with low refresh (60Hz is ubiquitous) and use nVidia's Fast Sync which works quite well but it requires a sustained fps x 3 rate (that would be more or less a constant fps rate of 180), because Fast Sync is nVidia's ACTUAL and REAL implementation of Triple Buffering for D3D.
5. For high refresh displays I would experiment with traditional VSYNC. For calculating input lag, the math would be:
For my 165Hz display for example: 1/165 * 1000 = that would yield +-6ms of input lag.

Pejole2165 · 09 Jun 2021

From what I have gathered from both Nvidia recommendation's and Guru3D, on a 165Hz display (G-Sync compatible), set V-Sync on in Nvidia control panel, but off in games, set maximum refresh rate to 3 - 5 below actual (so 160 - 162 for 165Hz).
On my Gigabyte G32QC (31.5", 165Hz, 1440P, Free Sync Premium VA monitor, connected with DP) this gives me the best display across games (FPS, RPG, sims) using both native display and DLSS with no tearing, smearing or visible ghosting and a frame time of an average 6.5ms, with an RTX2060 Super.
If you find the frame cap doesn't work for you, try RivaTuner's frame cap.
Windows settings are GPU Scheduling = ON, VRR = ON.

eLPuSHeR · 10 Jun 2021

Thank you very much Pejole2165.

eLPuSHeR · 10 Jun 2021

Ok.

So, I have found out that unless VSYNC in enabled in nVidia's CP alongside GSYNC mode, I still get some unpleasant tearings/artifacts when turning my head to the sides under csgo for instance. It seems frame capper is irrelevant if you have VSYNC OFF, but I have kept it 5 frames below maximum refresh rate just to be on the safe side.

Pejole2165 · 10 Jun 2021

From further reading (especially articles on Guru3d) I understand that the whole point of G-Sync, FreeSync, VRR is to even out frame times based on refresh rate (or as you pointed out a percentage/ ratio of max refresh rate available to the display device).
This has an effect on the FPS but is that is not the real purpose of the tech. I suppose setting the frame cap helps the tech work better since the GPU is not over rendering frames as much and it makes it easier to smooth the frame times since the range from lower to upper refresh rate is kept within the range available to the display.
Another thing I was looking into is the way games use the Windows display device to render content, such as windowed, full screen and full screen borderless as the G-Sync settings has two switches allowing you to turn it on/ off for full screen only or full screen and windowed mode.
The part where you mention turning your head side to side makes me think you are talking about using a VR device? If so I have never used one and wouldn't have a clue as to the best way to set that up.

eLPuSHeR · 11 Jun 2021

Good day.

I am not using any kind of VR. I meant moving the mouse around or doing strafing.

I have found out some games perform better than others using VRR. For instance, csgo is better with VRR because of increased input lag of vsync, but I notice increased stuttering under Grim Dawn, so I am running using in-game vsync (input lag is not an issue here). Your mileage may vary I guess.

Pejole2165 · 11 Jun 2021

Yeah, all hardware is slightly different and the combinations of hardware and software are probably innumerable, add to that each person perceives image, colour and motion differently and has different views on what they consider acceptable, it is a mine field trying to come up with a "one solution to suit all".
As far as lag goes the Nvidia settings have a latency setting you may want to play with, personally I find little difference between the values, maybe it is designed for higher than 165Hz displays?
Stuttering may not just be down to GPU settings, it could also be the PC's subsystem (disk IO, chipset performance, heat throttling with NVMEs, CPU architecture, core count, speed etc), but if you have found settings that work for you then all is good.

eLPuSHeR · 14 Jun 2021

Thanks again for the insight.