You can use VAAPI or NVENC for hardware encoding, I believe there are presets for that in the render dialog nowadays. I think that is or was broken in the AppImage though.
Using the GPU for actually processing heavy effects (like color correction, chroma keying, transformations etc) is currently not possible and the GPU processing option in the settings is broken. And many of these effects are single threaded on the CPU.
You can use VAAPI or NVENC for hardware encoding, I believe there are presets for that in the render dialog nowadays. I think that is or was broken in the AppImage though. Using the GPU for actually processing heavy effects (like color correction, chroma keying, transformations etc) is currently not possible and the GPU processing option in the settings is broken. And many of these effects are single threaded on the CPU.