Question / Help Irregular stuttering/low fps in preview/recording

m00sician

New Member
Hello!

I've had this issue for a while now and always thought that it's my capture card, but I went through 3 different capture cards now and the issue persisted throughout all 3 and 2 different PCs.

Basically, OBS has irregular stuttering or low fps in the preview and during recoding, even though it shows a stable 60fps with no dropped frames. I wouldn't really mind if its just the preview, but the recording also has these weird stutters. It's like the 60fps preview suddenly goes down to 45-50fps for a few seconds, then goes up to 60, and after a few moments it goes down to 45-50 again. Yet, it always shows stable 60fps.

It doesn't matter if I use x264 or NVENC, it doesnt matter which resolution I select or which framerate. If I play a 30fps game these laggs can hit even harder sometimes. I remember playing crash bandicoot was infuriating sometimes because of it. Yet OBS never showed any dropped frames or anything. My CPU load never exceeds 10-15% and usually hovers around 3-5%. I purchased AMCap to try and see if all my equipment is broken and I'm the unluckiest guy in the world or if the issue is with OBS and so far the issue has only appeared in OBS. AMCap works with fluid 60fps, no stuttering or fps drops at all.

Is there a way to fix it and make sure the preview playback is a fixed 60fps or am I just imagining things?
 

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  • 2017-11-20 16-14-38.txt
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Boildown

Active Member
Change the NVEnc preset to High Profile (HP) instead of Default.

16:14:39.729: [DShow Device: 'Cam'] settings updated:
16:14:39.729: video device: Logitech HD Pro Webcam C920
16:14:39.729: video path: \\?\usb#vid_046d&pid_082d&mi_00#7&328e2767&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{bbefb6c7-2fc4-4139-bb8b-a58bba724083}
16:14:39.729: resolution: 1920x1080
16:14:39.729: fps: 30.00 (interval: 333333)
16:14:39.729: format: I420

Change your webcam resolution to 960x540 instead of 1920x1080, or even smaller.

Does your capture device reside on USB, or is it PCIe? If USB, make sure its using a different root hub than your web cam.

The OBS statistics for the recording actually looked fine, so its possible its something else entirely, but the above are the closest thing we have to "best practices" for web cams, NVEnc recording, and USB capture cards.
 
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