Does this seem normal or should the performance impact from running OBS be less.
My hardware isn't great but should be good enough, i5 4670k, 16GB RAM, GTX 960 4GB, running Ubuntu 18.04 and Nvidia driver 430.x (long lived branch).
I notice that if I open a game and turn off vsync so the fps are uncapped the performance drops significantly simply by opening OBS. An example situation is a game running uncapped at 70fps, open OBS and it drops to 62, start recording with NVENC and it drops to 55 fps.
The drop in FPS seems to be highest when the GPU utilization goes above 96-98% but still occurs at low GPU load, even though the video engine utilization is only around 10% and the PCI bandwidth is under 5% according to the info in Nvidia X server settings.
I was under the impression that OBS had little performance impact from simply running (2-3%), and no (or virtually no) FPS impact by recording with NVENC since NVENC uses a dedicated chip for that purpose.
This is with a GTX 960 that shouldn't have the option to use CUDA cores to encode, like the "new" NVENC does on Windows with the Pascal GPU's and newer, but as far as I know that new NVENC that uses CUDA cores isn't available on Linux at all, at least with OBS.
I tested this with a fresh install of OBS 24.0.3, capturing the game window as Xcomposite, NVENC at CBR, 3500Kbps, preset Max Quality, profile high, Max B-frames 2, encoding 720p at 60FPS. OBS was showing about 3% CPU use.
Log file included.
My hardware isn't great but should be good enough, i5 4670k, 16GB RAM, GTX 960 4GB, running Ubuntu 18.04 and Nvidia driver 430.x (long lived branch).
I notice that if I open a game and turn off vsync so the fps are uncapped the performance drops significantly simply by opening OBS. An example situation is a game running uncapped at 70fps, open OBS and it drops to 62, start recording with NVENC and it drops to 55 fps.
The drop in FPS seems to be highest when the GPU utilization goes above 96-98% but still occurs at low GPU load, even though the video engine utilization is only around 10% and the PCI bandwidth is under 5% according to the info in Nvidia X server settings.
I was under the impression that OBS had little performance impact from simply running (2-3%), and no (or virtually no) FPS impact by recording with NVENC since NVENC uses a dedicated chip for that purpose.
This is with a GTX 960 that shouldn't have the option to use CUDA cores to encode, like the "new" NVENC does on Windows with the Pascal GPU's and newer, but as far as I know that new NVENC that uses CUDA cores isn't available on Linux at all, at least with OBS.
I tested this with a fresh install of OBS 24.0.3, capturing the game window as Xcomposite, NVENC at CBR, 3500Kbps, preset Max Quality, profile high, Max B-frames 2, encoding 720p at 60FPS. OBS was showing about 3% CPU use.
Log file included.
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