The program Kdenlive during rendering only uses between 10-20% GPU. With ffmpeg the utilization is at 100%. Why Kdenlive doesn’t use the whole GPU.
I use Debian 12 with KDE, GeForce RTX 3060 12 GB, cuda, MLT, FFmpeg is installed.
The error was not in the GPU acceleration, but in the settings of my project.
When importing a clip, Kdenlive asks e.g. “Switch to the profile 2704x1520 59.94fps (2704x1520, 59.94fps) of the clip (test.MP4)?”, which I ignored since I wanted the clip to be 60fps.
When I adjusted the profile to the current clips at 59.94fps, Kdenlive rendered at 133 fps and had a GPU utilization between 60 and 70%.