Help Understanding G-Sync Windowed 40fps behavior

[jorimt]

For Dolphin Emulator I've tried different backends (D3D11, 12, OGL, Vulkan), borderless/exclusive, and different emulator release versions with no luck. I'm starting to think my older g-sync monitor doesn't play well with certain applications. It refreshes precisely at 59.89hz.

Is your monitor model only 60Hz? Because that would explain some things, if so. Either way, the monitor model should always be included in the OP for reference, regardless (not all VRR monitors are created equal).

[ZTylerDurden]

Is your monitor model only 60Hz?

It goes up to 144hz although for 30fps content I prefer to set it to 60hz if I decide to game-stream the video content to other devices.

It's one of the original panels where you had to DIY the fpga gsync module. ASUS VG248QE.

[jorimt]

It's one of the original panels where you had to DIY the fpga gsync module. ASUS VG248QE.

I'm pretty sure that model doesn't support LFC, hence you're particular issues (at least partially) in that scenario. And even if your monitor did support LFC, you'd want to use 120Hz with 30 FPS VRR, at minimum.

[ZTylerDurden]

I'm pretty sure that model doesn't support LFC, hence you're particular issues (at least partially) in that scenario. And even if your monitor did support LFC, you'd want to use 120Hz with 30 FPS VRR, at minimum.

Interesting. So if the pendulum demo with Gsync works at 60hz min max test 30-60fps, what does LFC have to do with the emulator not activating gsync?

[jorimt]

Interesting. So if the pendulum demo with Gsync works at 60hz min max test 30-60fps, what does LFC have to do with the emulator not activating gsync?

For one, I don't know if G-SYNC is actually working for you in the pendulum demo, and as for the emulator not activating G-SYNC, you need to first rule out if it's your monitor not being able to engage G-SYNC with 30 FPS Dolphin games at a physical 60Hz; try 60 FPS Dolphin games at a physical 120 or 144hz, if you haven't already.

Historically, monitors with G-SYNC modules can typically reach a minimum physical variable refresh rate of 30Hz (say 30 FPS @60Hz or @120Hz, etc), and anything below that, they require LFC to keep VRR engaged. In fact, nowadays, many hardware G-SYNC monitors, especially the higher refresh rate variety, engage LFC much earlier, say at 45Hz, 60Hz, sometimes higher.

So if your monitor doesn't support LFC and it is indeed functioning at 30Hz VRR (or thereabouts; it could physically bottom out a little over 30 with VRR active), it means anything even a fraction of a HZ below that, and G-SYNC will disengage, reverting to no-sync with G-SYNC on + V-SYNC off or standalone V-SYNC with G-SYNC on + V-SYNC on.

I happen to have Dolphin and Crystal Chronicles, and with my setup (see my sig) at a physical 360Hz refresh rate with G-SYNC + NVCP V-SYNC, I'm getting 30 FPS with an effective 60Hz VRR LFC output, as expected for my particular configuration.

[ZTylerDurden]

For one, I don't know if G-SYNC is actually working for you in the pendulum demo,

I have the g-sync indicator setting turned on and it displays the g-sync watermark for the pendulum test among other apps. It's clearly g-sync in action.

try 60 FPS Dolphin games at a physical 120 or 144hz, if you haven't already.

Tried Bloody Roar Primal Fury at 60fps 120hz. No g-sync watermark although it plays fine fullspeed and I don't get any heavy tearing unless I switch to 60hz (which is expected without VSYNC ON).

So if your monitor doesn't support LFC and it is indeed functioning at 30Hz VRR (or thereabouts; it could physically bottom out a little over 30 with VRR active), it means anything even a fraction of a HZ below that, and G-SYNC will disengage, reverting to no-sync with G-SYNC on + V-SYNC off or standalone V-SYNC with G-SYNC on + V-SYNC on.

This makes sense and would make me believe is the cause of the issue. But this would mean Bloody Roar at 60fps render should activate g-sync since we're not messing with 30fps boundaries unless I'm misunderstanding what you're saying.

I happen to have Dolphin and Crystal Chronicles, and with my setup (see my sig) at a physical 360Hz refresh rate with G-SYNC + NVCP V-SYNC, I'm getting 30 FPS with an effective 60Hz VRR LFC output, as expected for my particular configuration.

Thanks for testing that! I also got confirmation elsewhere that g-sync activated just fine with Dolphin and another 30fps game. I think that getting a new monitor would be the only way to really know. Or DDU and nuke my drivers.

[jorimt]

Thanks for testing that! I also got confirmation elsewhere that g-sync activated just fine with Dolphin and another 30fps game. I think that getting a new monitor would be the only way to really know. Or DDU and nuke my drivers.

All I can share at this point is the settings I was using for Dolphin windowed (with G-SYNC + NVCP V-SYNC, driver version 572.75)...

it seems Dolphin still uses a legacy flip model for windowed mode, at least on my configuration, since enabling/disabling the Borderless Fullscreen toggle in the Dolphin settings under Graphics > Advanced, and/or Variable refresh rate and Optimizations for windowed games under System > Display > Graphics > Default graphics settings did not affect whether VRR would engage when the game window was focused for me.

The only thing that ultimately worked for me was having Enable for windowed and full screen mode set in the NVCP under Display > Set up G-SYNC, at which point my monitor would LFC to 60Hz VRR with 30 FPS at a physical 360Hz when the game window was focused on, and when it wasn't, the desktop would revert to fixed refresh rate mode.

Instead of the above though, my recommended settings for legacy borderless/windowed VRR in entry #5 of my Closing FAQ should be used to prevent VRR from applying to anything other than the intended app when focused:
https://blurbusters.com/gsync/gsync101- ... ttings/15/

That said, since my monitor uses DSC to reach 360Hz, I don't believe it supports MPO (that can be enabled/disabled via a regedit), which is a newer behavior that can affect borderless/windowed mode as well, sometimes in unexpected ways depending on the configuration, so what works for me in this case may or may not for someone with a different monitor or GPU model, and/or driver or OS version.

[RealNC]

it seems Dolphin still uses a legacy flip model for windowed mode

Vulkan?

[jorimt]

Vulkan?

Vulkan is indeed an available backend in Dolphin, but I was testing with DX11 in this case:

[ZTylerDurden]

Instead of the above though, my recommended settings for legacy borderless/windowed VRR in entry #5 of my Closing FAQ should be used to prevent VRR from applying to anything other than the intended app when focused:
https://blurbusters.com/gsync/gsync101- ... ttings/15/

Absolutely CRUSHED IT. Faq #5 worked to use nvidia inspector. I got g-sync active now in Dolphin. F------ excellent work.

Only thing now is that I get slight flicker at 30fps (60fps games are fine). I'll chalk this one up to being my old monitor which is fine. Totally playable. Screen tearing is gone.