Help Understanding G-Sync Windowed 40fps behavior

[ZTylerDurden]

I'm playing a gamecube-emulated game which I require in windowed mode. The game runs natively at 30fps. I have G-sync configured only for full-screen mode although it seems to activate anyway. When running the game, per my screenshot and UFO test, the whole desktop renders at 40fps. If I full-screen the game, my desktop renders at 60fps which is preferred in my scenario (except I require windowed mode).



If I disable G-sync for my monitor, I render 60fps regardless if the game is windowed or full-screen. Basically, the solution is turning off G-sync. Why?

Can someone explain why G-sync is rendering 40fps and how to prevent it from doing that while keeping G-sync on? Ideally it'll render my desktop at 60fps with the emulator running windowed. Configuring G-sync for both windowed and full-screen in NVCP doesn't make a difference.

[RealNC]

Are you forcing a vsync setting in the nvidia control panel maybe? It can cause weird issues if you don't make sure to set it to "use application setting."

Also check if you have set an FPS cap for background apps.

[ZTylerDurden]

Are you forcing a vsync setting in the nvidia control panel maybe? It can cause weird issues if you don't make sure to set it to "use application setting."

Also check if you have set an FPS cap for background apps.

Vsync is definitely set to "use application setting". If it was an FPS cap on background apps it would happen with g-sync off..which it doesn't cap with g-sync off.

Doesn't this have to do with g-sync identifying my 30fps game and trying to work its way down to match the frame rate of my 30fps game, but my g-sync module only goes down until 40fps unless I have g-sync ultimate fpga? Even if that's the case, I have g-sync configured only to full-screen so I don't know why it's even behaving that way if it's a windowed game.

[RealNC]

Doesn't this have to do with g-sync identifying my 30fps game and trying to work its way down to match the frame rate of my 30fps game, but my g-sync module only goes down until 40fps unless I have g-sync ultimate fpga? Even if that's the case, I have g-sync configured only to full-screen so I don't know why it's even behaving that way if it's a windowed game.

I don't know what causes it then. But the "windowed g-sync" setting isn't really for modern windowed mode. It's for legacy windowed mode that wasn't using a modern frame presentation model.

Have you checked if the VRR setting in Windows itself has an effect on this? It should be in the "graphics settings" in the Windows Settings app.

[ZTylerDurden]

I don't know what causes it then. But the "windowed g-sync" setting isn't really for modern windowed mode. It's for legacy windowed mode that wasn't using a modern frame presentation model.

This is good to know

Have you checked if the VRR setting in Windows itself has an effect on this? It should be in the "graphics settings" in the Windows Settings app.

Well I'll be damned. This was the culprit. Do you know why it does this and if it's intended?

Also, I'm pretty sure I've had g-sync+VRR setting on for this exact game but behaving great--I just haven't been able to recreate the scenario and ended up with these 40fps issues.

Windows, man. I know it has good intentions but it ends up creating more confusion than clarity with its layers.

[RealNC]

Well I'll be damned. This was the culprit. Do you know why it does this and if it's intended?

Who knows All I know is that can keep g-sync working in more scenarios (like when an overlay is shown on top of a game.) But that setting is pretty much undocumented and it doesn't do what it says it does.

[ZTylerDurden]

I tested it a bit further and there's a sub category on that same graphics section in W11 which was the real cause. I had to toggle off "optimizations for windowed games"


I didn't add that app to the list but Windows figured it was a good idea . It also looks like Windows doesn't let you remove it from the list either.

[jorimt]

I tested it a bit further and there's a sub category on that same graphics section in W11 which was the real cause. I had to toggle off "optimizations for windowed games"


I didn't add that app to the list but Windows figured it was a good idea . It also looks like Windows doesn't let you remove it from the list either.

Yup, it changes the flip model for supported borderless/windowed apps:
https://support.microsoft.com/en-us/win ... 389e535952

[RealNC]

I tested it a bit further and there's a sub category on that same graphics section in W11 which was the real cause. I had to toggle off "optimizations for windowed games"


I didn't add that app to the list but Windows figured it was a good idea . It also looks like Windows doesn't let you remove it from the list either.

Doing this is bad for perf and latency. You want that option on, otherwise games that use old-style frame presentation model will perform worse compared to exclusive fullscreen. VRR also won't be working even if the window is in the foreground.

[ZTylerDurden]

Doing this is bad for perf and latency. You want that option on, otherwise games that use old-style frame presentation model will perform worse compared to exclusive fullscreen. VRR also won't be working even if the window is in the foreground.

Turns out G-sync was never activated in the first place in contrast with my initial post.

The issue is that for whatever reason, G-sync does not kick in with Dolphin Emulator. With no g-sync, windowed optimizations causes this 40fps bug with screen tearing. Turning windowed opt. off gives me back frame rate control at 60fps baseline to prevent tearing and stuttering with RTSS.

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.