Low Rendering speed on high-end pc

Hi Kdenlive.

My rendering speed is quite low. 4k 9:16 aspect ratio 60fps is the project settings. The edit is 14 min long.
I tried using parralel -16 and -1 threads. Encoder speed ultrafast with 16 threads.

The render time is 1h20min at 4-6 fps.

Version 23.08.5

I use a i7 13700kf with an rtx 4090. 64gb ram and using m.2 as ssd.

I saw a video on youtube, he was using a gtx 970 his project was 8 minutes long and it took him 4 min to render.

The only effects i used on the project is position and scale movement. The rush video is 60fps 4k 16:9 from a gameplay

With all said i wonder why it render that slow?

Have you tried changing the number of threads under the encoder options? There is a more settings section you can check box to see more options

you might try parallel processing too but im not sure of the specifics regarding either of these settings. Changing encoder threads seemed to help with my 5900x

EDIT: Just noticed you mentioned the threads my bad

Thats gonna be a tough encode either way on CPU, if you want it to be fast you can try using GPU encoding but be aware its technically lower quality. The hardware encoding options might be what youre looking for to render “quickly” in 4k. The NVENC encoder should be quick about it and has a few options in the HW accelerated section.

I just did a quick test with my RX6800 and can render a 1min 4K 60fps H264 video at 32fps with VAAPI. NVENC should do it even faster as the AMD H264 encoder isnt nearly as good.

EDIT: Reading this thread https://www.reddit.com/r/kdenlive/comments/ka0aak/kdenlive_gpucpu_use_threads_mlt_and_ffmpeg_tips/

I set Threads and Parallel threads higher (between 8-12 for each one seemed ok) and that doubled my vaapi encode speed to 60fps. Seems that MLT tends to be the bottleneck here and that it generally uses a single thread

EDIT: Just tried a CPU render on my 5900x and i get about 4-8fps so no real difference from you. I think the YT video you watch either had a very powerful CPU or used GPU encoding

No nothing has changed. I tried Hardware Accelerated. I tweek Parralel on off -1/-16. I tried also to put it in 16:9 with no effect, still 1h30 for 14 min long.

My cpu and gpu works at 5-10%.

hmm…strange, honestly beyond that we might need someone more experienced with kdenlive to chime in with their thoughts :face_with_diagonal_mouth: