Video Engine Utilization % when rendering video

GPU Unix Graphics Linux
#1

First of all I would like to apologize if this has been asked before, as I couldn’t find an answer via the search, and also I wasn’t sure which section to put it in.

My question is: When rendering video with NVENC enabled on my Quadro K620, if I go into nvidia-settings (Nvidia’s control panel for Linux), it shows a percentage next to GPU Utilization and Video Engine Utilization. What puzzles me is that the percentage is always really low. GPU Utilization barely goes past about 4%, and Video Engine Utilization barely goes past about 10%.

Why is my Quadro not utilizing its’ full power? Is this down to a bottleneck with my CPU, drivers, video editing software (I’ve tried both Kdenlive and Shotcut and the percentage is still low), or something else? Does anyone else have experience with this?

When rendering (using all 4 cores of my i5 2500s, and enabling the parallel processing option in the video editing software), my CPU always works at near full power, but the GPU doesn’t. I have 8gb of ram, which is never maxed out when rendering, and neither is the ram on the GPU, so it can’t be that.

I’d love to know how to increase the percentage of the GPU utilization, as this would then surely get the full rendering speed from the Quadro.

I’m using driver version 455.38

Thanks in advance.

#2

This solely depends on the application used to process the material how and to what extent the gpu is used. So you have to check there if nvenc is used at all.

#3

Thanks for your quick reply.

Kdenlive is the main application I’m using, and I have selected the NVENC H264 preset. It’s definitely using NVENC, but I was just wondering why it isn’t fully utilizing the GPU’s power. I read here, under the “What you want” section, that apparently the GPU can be used for rendering ffmpeg video parts, but MLT still needs CPU processing. However, it isn’t the CPU that seems to be the problem, so does that mean that an ffmpeg setting is what’s causing the slowdown?

Any help would be appreciated :)

Update:

I’ve used some different rendering settings from the link above, and this seems to have sped it up a bit, but even so, it’s still only utilizing 17% of the video engine. I’d love to figure out where this bottleneck is coming from. It’s a shame to only have about 20% of the speed the card is capable of, when the CPU is being fully utilized.

#4

If you use heavy effects so the cpu is always fully loaded, it just can’t feed the gpu enough frames to encode.

#5

IDK if that’s still available, but you could try using the movit library with mlt and kdenlive to offload also the effects processing to the gpu.

#6

Thanks again for the quick reply. I will try using the movit library and see if this improves the performance. I suppose I could also try to assign only 2 CPU cores to Kdenlive and see if that shifts more of the rendering over to the GPU. Thanks for your help @generix