Emulator Issues #12390
D3D11 halfs framerate in windowed mode
What's the problem? Describe what went wrong.
The first thing I noticed a while ago is that in windowed mode, the max fps is limited by the refresh rate of my monitor (144Hz). I don't remember seeing this behaviour before but when I tested 5.0, I got the same result so I guess this could be a change in Windows. This causes the framerate to limited at half the refresh rate (72Hz) when a game shows duplicate frames and Dolphin is configured to show them.
But D3D11 seems to half that in windowed mode. The full framerate I get is 36fps in windowed mode. That means that when a game has duplicate frames and Dolphin shows duplicate frames and runs in windowed mode, the max fps I get on my 144Hz screen is 18fps.
BTW: All games run at 300+fps when in fullscreen.
What steps will reproduce the problem?
Running D3D11 in windowed mode, enable present duplicate frames for extra slowdown(only if a game actually shows duplicate frames).
Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.
Is the issue present in the latest stable version?
If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)
I first got 5.0-11524 as bisect(the adition of present duplicate frames) but later found out this isn't the reason why D3D11 runs at half speed compared to the rest.
I don't have the time right now to further bisect but 5.0-8828 had the issue.
If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer
[Attach any fifologs if possible, write a description of fifologs and screenshots here to assist people unfamiliar with the game.]
What are your PC specifications? (CPU, GPU, Operating System, more)
r5 3600, GTX 1060, W10
Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)
[Anything else here]
#4 Updated by ZephyrSurfer 19 days ago
What may be relevant is driver version.
With Nvidia driver 461.09 and later it can use MPO so finally a windowed application can skip the desktop compositor.
Can you try your current version when windowed mode Dolphin is the active window and again when it's not the active window.
And try with the later Nvidia >= 461.09 with the the same steps above. (Try Nvidia V-sync controls forcing off if behaviour doesn't change)