FSO vs. Exclusive Fullscreen

[TTT]

For Apex you need to figure out how to turn off FSE as well, it forces on now when you turn it off via .exe or registry.

You mean Disable FSO (plus other things) so that you are in FSE.

Mine runs in FSE fine and yes, I do notice a difference.

What version of windows do you have? How do you understand that the application works in the FSE, except for your "feelings"?

I'm W10 up to date.

FSO is on by default on all games, its a Windows 10 function that overides the fullscreen mode of a game and forces it into Microsofts hybrid borderless. Its literally Borderless but they say the same input lag as fullscreen, but its not. It was basically introduced into Windows 10 to make the gamebar overlay work better.

You can tell its on because you can alt+tab out of the game instantly and the screen won't flicker black, also if you change volume the dial will come up over the front of the game when FSO is on, exclusive fullscreen will have no overlay at all.

Its not just 'feel', its a non native change Windows is making to the game. Also now DX12 games (I'm not sure if its all of them or just some) don't have fullscreen exclusive at all, it is just using FSO and the game doesn't actually have an exclusive fullscreen mode.

[jorimt]

FSO is on by default on all games, its a Windows 10 function that overides the fullscreen mode of a game and forces it into Microsofts hybrid borderless. Its literally Borderless but they say the same input lag as fullscreen, but its not. It was basically introduced into Windows 10 to make the gamebar overlay work better.

The Windows 10 hybrid borderless/exclusive fullscreen mode, to my knowledge, effectively functions as adaptive DWM; it engages the compositor when certain overlays pop up and/or when the game window is unfocused, and then disengages it when the game window is focus on, reverting to exclusive fullscreen behavior. Basically, it toggles between two flip modes.

Beyond that, I don't believe there is a functional or performance difference during gameplay itself, at least one that has been proven or one that I have ever felt.

That said, there are occasional FSO interactions with specific games that can create odd behaviors, such as in the Dark Souls engine, which forces higher-than-60Hz monitors running G-SYNC to 60Hz if FSO is enabled (one of the only game engines I disable FSO for). Additionally, there was a glitch in older Windows 10 builds where G-SYNC would only function in DX9 games if FSO was enabled, but I believe they have since fixed this.

Microsoft also has a technical article that details the available flip modes in Windows 10 that I'd link here for reference, but I can't seem to find it again.

[TTT]

FSO is on by default on all games, its a Windows 10 function that overides the fullscreen mode of a game and forces it into Microsofts hybrid borderless. Its literally Borderless but they say the same input lag as fullscreen, but its not. It was basically introduced into Windows 10 to make the gamebar overlay work better.

The Windows 10 hybrid borderless/exclusive fullscreen mode, to my knowledge, effectively functions as adaptive DWM; it engages the compositor when certain overlays pop up and/or when the game window is unfocused, and then disengages it when the game window is focus on, reverting to exclusive fullscreen behavior. Basically, it toggles between two flip modes.

Beyond that, I don't believe there is a functional or performance difference during gameplay itself, at least one that has been proven or one that I have ever felt.

That said, there are occasional FSO interactions with specific games that can create odd behaviors, such as in the Dark Souls engine, which forces higher-than-60Hz monitors running G-SYNC to 60Hz if FSO is enabled (one of the only game engines I disable FSO for). Additionally, there was a glitch in older Windows 10 builds where G-SYNC would only function in DX9 games if FSO was enabled, but I believe they have since fixed this.

Microsoft also has a technical article that details the available flip modes in Windows 10 that I'd link here for reference, but I can't seem to find it again.

I only really play online FPS games and I find turning it off makes the mouse movement sharper. With it on in comparison to it off you can feel added drag on the mouse like a type of mouse smoothing.

This article basically has everything you need to know in it:
https://devblogs.microsoft.com/directx/ ... mizations/

On the game screen it does revert to FSE behaviour but it still isn't actual FSE.

"When using Fullscreen Optimizations, your game believes that it is running in Fullscreen Exclusive, but behind the scenes, Windows has the game running in borderless windowed mode."

[howiec]

Are you just using the .exe tickbox to disable it?

Yes. I typically also select Application under "Override high DPI scaling..." and Gamebar is disabled.

Also, no in-game overlays are enabled (e.g. Origin) but that may not matter depending on which one you use.

[howiec]

this is fse 100%
version 2004? I'll have to try. thanks for the information.

Np, but just reiterating, FSE was also working for me on several of the previous versions of Windows including v1909.

[jorimt]

This article basically has everything you need to know in it:
https://devblogs.microsoft.com/directx/ ... mizations/

[...]

"When using Fullscreen Optimizations, your game believes that it is running in Fullscreen Exclusive, but behind the scenes, Windows has the game running in borderless windowed mode."

The article goes on to explain the below after your quoted sentence...

To get back this performance overhead, we enhanced the DWM to recognize when a game is running in a borderless full screen window with no other applications on the screen. In this circumstance, the DWM gives control of the display and almost all the CPU/GPU power to the game. Which in turn allows equivalent performance to running a game in FSE. Fullscreen Optimizations is essentially FSE with the flexibility to go back to DWM composition in a simple manner. This gives us the best of both worlds with performance and other features that require the DWM, such as overlays. When an overlay such as the Game Bar is present, the DWM reassumes control of the display, and a slight performance overhead is incurred so that the overlay can be composited on top of the game in a safe and stable way.

In other words, as I said, it's effectively adaptive DWM while retaining the benefits of exclusive fullscreen when the game window is focused.

She didn't delve into the specifics of the flip modes involved, which, when specified, really makes the focused FSO mode virtually the same as exclusive fullscreen. Again, I wish I could find that Microsoft article on the different flip modes available to Windows 10 to source for reference.

You're obviously free to disable it though. I simply haven't noted enough of a difference between FSO on/off in games to disable it myself (barring when it causes obvious issues, aka DS/Sekiro), especially in more recent Windows builds.

[howiec]

Beyond that, I don't believe there is a functional or performance difference during gameplay itself, at least one that has been proven or one that I have ever felt.
...
Microsoft also has a technical article that details the available flip modes in Windows 10 that I'd link here for reference, but I can't seem to find it again.

Noticing a difference depends on a multitude of factors, including as you mentioned the game.

Not sure if you're referring to this:
https://docs.microsoft.com/en-us/window ... wap_effect

And for those who are not familiar with the flip model:
https://docs.microsoft.com/en-us/window ... flip-model

[jorimt]

Not sure if you're referring to this:
https://docs.microsoft.com/en-us/window ... wap_effect

And for those who are not familiar with the flip model:
https://docs.microsoft.com/en-us/window ... flip-model

Those pretty much contain the same info, yes.

But I found what I was previously referring to. It was actually a video in a user's post:
viewtopic.php?f=2&t=4890&p=37749&hilit= ... ion#p38373

phpBB [video]

It's more specific to the flip modes available to DX12 in Windows though.

That said, beyond subjective per-user reporting, there's no easy technical test to definitively prove FSO is worse than exclusive fullscreen in any/all circumstances and in what respect.

All I can say is, again, as I told @TTT, I subjectively haven't felt a difference in more recent Windows builds, and, further, it has never visibly increased input lag in any of my previous high speed tests.

[TTT]

This article basically has everything you need to know in it:
https://devblogs.microsoft.com/directx/ ... mizations/

[...]

"When using Fullscreen Optimizations, your game believes that it is running in Fullscreen Exclusive, but behind the scenes, Windows has the game running in borderless windowed mode."

The article goes on to explain the below after your quoted sentence...

To get back this performance overhead, we enhanced the DWM to recognize when a game is running in a borderless full screen window with no other applications on the screen. In this circumstance, the DWM gives control of the display and almost all the CPU/GPU power to the game. Which in turn allows equivalent performance to running a game in FSE. Fullscreen Optimizations is essentially FSE with the flexibility to go back to DWM composition in a simple manner. This gives us the best of both worlds with performance and other features that require the DWM, such as overlays. When an overlay such as the Game Bar is present, the DWM reassumes control of the display, and a slight performance overhead is incurred so that the overlay can be composited on top of the game in a safe and stable way.

In other words, as I said, it's effectively adaptive DWM while retaining the benefits of exclusive fullscreen when the game window is focused.

She didn't delve into the specifics of the flip modes involved, which, when specified, really makes the focused FSO mode virtually the same as exclusive fullscreen. Again, I wish I could find that Microsoft article on the different flip modes available to Windows 10 to source for reference.

You're obviously free to disable it though. I simply haven't noted enough of a difference between FSO on/off in games to disable it myself (barring when it causes obvious issues, aka DS/Sekiro), especially in more recent Windows builds.

Disabling it is the problem, some games now force it on even when it is disabled via .exe or registry. I'm not sure if its Windows forcing it on or the game though.

[jorimt]

Disabling it is the problem, some games now force it on even when it is disabled via .exe or registry.

Yup, another reason I no longer personally bother with it unless it causes an obvious issue in the game I'm playing (aka Sekiro refresh rate lock) and allows override via the existing per-exe option.