Bug Report UI Freezing at 60fps

[PowerMeep]

Log File:
https://gist.github.com/4af3015bac1328bd12c153adc15961c9

Possibly related to this post:
https://obsproject.com/forum/threads/ui-freezing-my-obs-fixed.60648/

Just installed a new StarTech PEXHDCAP60 in my capture PC. When I add it to a scene in OBS Studio with a 30fps profile, it works fine. However, if I set the profile to 60fps (I've tested both 480p and 720p), the UI slows to a crawl. Any menu takes a solid 10-20 seconds to appear or disappear, and I'm also mostly unable to move the window itself. Occasionally, other Windows Explorer entities are affected as well.

I've found that if I disable the preview, the UI will begin to respond normally again. I don't think this affects the video output to either the stream or the file.

This problem is not present when using an Elgato HD60 at 720p 60fps or at all in OBS Classic.

I feel like it has something to do with my computer being unable to redraw the screen with all the data it's being given, which from my understanding is pre-encoded from the Elgato but raw from the StarTech card and "encoded during preview" in Classic. Are there some settings I can tweak to make this cooperate in OBS Studio the short term?

 

[PowerMeep]

Update 1: Tried setting my renderer to OpenGL. It did not solve the issue. I also tried installing an older version of Direct X, but OBS doesn't seem to want me to use anything but DX11.

Update 2: Was able to mitigate a lot of the waiting by disabling almost all Windows Visual Effects (need "desktop composition" and "visual styles" in order to keep Win7 rendering offscreen items, as well as Aero theme) as well as transparency. Still noticing a menu delay and substantial fps drop when the preview is enabled, though.

Update 3: Both the Win7 Basic and Classic themes stop the windows and menus from seizing up, and at that point it just becomes an fps drop. However, this solution raises the issue that Win7 won't render offscreen windows in these themes. To anyone else with this problem and without the need to capture offscreen, Consider disabling Aero on Win7. I haven't been able to do thorough testing on Win8+, but it seems as though the high-contrast themes use a different engine.

Update 4: I can bring the fps back up while the preview is enabled by making the preview reeeeeeeally small. It's definitely something to do with the rendering of the preview. I seem to get the fps higher using a projector window than the built-in preview.

 

[PowerMeep]

Final Update: got a dinky little graphics card, problem solved. Integrated graphics could not handle the raw preview. Would still be nice to be able to enable encoding during the preview again.