SUMMARY

I'm using Kdenlive 20.04.0-1 in Manjaro from its official repository and it's been choppy when previewing and when reproducing/playing it, with 1:1 (1080p) and with no Proxy files.

Anyway I think that it shouldn't be that way with the hardware I have:
CPU: AMD Ryzen 3800X, 8 dual cores
GPU: NVIDIA GP106
16 GB RAM
Nouveau drivers for Nvidia GPU, but with privative drivers is the same, also with GPU acceleration.

In fact, appimage of the version 19.08 works significantly better, so I have thought this could be a bug of 20.04 version (but 20.07 from Git and appimage for 20.04 is choppy as well).

I think the hardware I have is sufficiently good for this kind of work.



STEPS TO REPRODUCE

1. Enter two videos files, with no more than 1080p quality.
2. Enter an audio file.
3. Split the video files on smaller regions.
4. Apply rescaling and transforming effect to a video file on the timeline.


OBSERVED RESULT

The playing and previewing is very choppy and often makes tiny stops. This tiny stops are more often when arriving to a cut of video (I mean the limits of the regions of a splited file).
It only works smooth if I put the preview quality in 270p, what has a extremely odd resolution.


EXPECTED RESULT

It's expected that with the hardware I have, any kind of video production would go smooth, at least with such a simple project.
Seems that Kdenlive does not use/optimize the hardware resources, as this is not such bad hardware.

Also having to always use proxy files is significantly tedious, it's not a solution, but a patch.


SOFTWARE/OS VERSIONS

Linux: Manjaro MATE 20.0.1
Kdenlive version: 20.04.0-1, from Manjaro's "extra" repository


ADDITIONAL INFORMATION

I have observed that appimage of version 19.08 works quite better, but versions (no matter if appimage or official/unofficial repos) at least upper than 20.04 works worse.

I have videos of the comparison of 18.09 and 20.04< if this could help.