Sorry for the bump.
I believe I have found a solution, at least with the use of a capture card. I experienced this issue a while back and even made a post on it, then figured out that enabling 'Buffering' on the capture card fixed it.
I am currently using an AverMedia GC553G2 (HDMI 2.1), and running a monitor in native 1440p 240Hz using loop-through (no cloning because I don't like latency). I was recently messing around with CS2, and during my tuning, I disabled fullscreen optimizations on the game exe. As I was playing a DM, it hit me, what if the emulation that Windows does by default with FSO is the reason that the "Buffering" option in OBS has to be enable? So I went in to the capture card settings in OBS and changed buffering from 'Enabled' to 'Disabled'.
I set OBS recordings to "use stream encoder" so I can record exactly what my stream would see. I then did some recordings and testing with, CS2, QuakeLive, Quake Champions, DOOM Eternal, and Cyberpunk 2077 - All with the "Disable Fullscreen Optimizations" box checked on the respective exe's. After hours of testing the issue was gone! I have been recording and testing ever since and the 60FPS frame pacing issue seems to be fixed.
I'm on Windows 11 Pro 24H2 build 26100.6584 with Windows Feature Experience Pack 1000.26100.234.0
My capture card configuration in OBS is as follows:
- Resolution: 2560x1440
- FPS: 60 (because I am streaming at 60FPS)
- Video Format: Any
- Color Space: Default
-Color Range: Default
Buffering: Disabled
To disabled Fullscreen Optimizations you will need to do it on each of the games exe's:
https://imgur.com/a/XPNRVyX - So with the box "checked" it will be disabled. By default it is enabled (the box is unchecked).
Without getting too into it. What FSO in W10/11 does is runs the game in fullscreen-window, but "emulates" Fullscreen Exclusive. This also changes the flip-model that is used. Disabling Fullscreen Optimization (the box is checked) makes the game run in Fullscreen Exclusive mode. Where the GPU is communicating directly with the game render, and not going through a WDM emulation layer. This also changes the flip-model back to the "legacy" FSE model. If this does indeed fix it consistently for others, suspect that it is that 'emulation' layer that Windows is doing is the reason for the frame pacing inconsistency. With FSO, Windows is attempting to lower latency. Instead it seems to be causing frame pacing issues.
I'm really curious to have others with this issue, specifically with a capture card, to test this as well! So far it's been clean for me. If that changes I will report back.