QuickSync suddenly struggles heavily nearing 1080p60fps, but only on Linux

gairisiuil

New Member
So I have a very limited system (laptop) with an i7-8550U for a CPU (UHD 620) and no graphics card. My distro is Debian 12 with the XFCE environment. I'm using the OBS Flatpak.

QSV can record 1080p60 well enough for my use case on Windows, but for some reason it struggles heavily at 1080p 45fps (roughly) and above on Linux. At 1080p 40fps and 1536x864 60fps, the recording is smooth enough, but it turns into a slideshow very suddenly for some reason.

Example log (it says each recording has QPI/QPB/QPP of 23, but it was actually just CQP set to 27.)

The most perplexing part is that even when I set the bitrate to 500kbps or something, the encoder still overloads and I still get the same slideshow, despite OBS using 4% cpu with preview on while I'm not recording (with video setting set to 1080p60.)

Normally the solution would be to just use Windows, but I do not like Windows anymore because of the fact that on my system, nearly every GUI has some amount of painful lag compared to Linux, and I can't go back. Ideally I want to avoid that. Even after research, though, I can't find any solution.

I feel like there's something about the way the application provides the frame data to the encoder during recording that is causing this to happen, but ultimately I need someone smarter than me to tell me what it is.
 
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gairisiuil

New Member
I have isolated my issue. The slideshow only applies to maximized windows for some reason. A window resized to fill the screen does not have this issue and records 100% smoothly at 1080p60fps. It's really very confusing.
 
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