Correct configuration for decoding 7 video pipelines

Hi. I need to decode 7 FULL HD/60fps pipelines. In my first attempt i used one 2060 SUPER and it turns out that there is no enough power to decode 7 pipelines, it worked just with 6. So i added second 2060 SUPER to my machine. There is my current nvidia-smi:


So i tried to decode with new configuration but already at 5 pipelines decode started to delay. This is nvidia-smi when i decode 5 pipelines:

But it’s very strange because when i used just one graphic cadr it was utilized at 88% percents when i decoded 6 pipelines.
And what is more strange it’s what they do during decode. One of them just decode something (look below) and second just copying something…

And one more thing. When i start to decode first pipelines, one of GPU disables it’s coolers.

To decode i use nvdec module from GStreamer, which uses nvidia sdk codec inside.

So i have a few questions:
1.How to configurate my GPUs correctly? i want to split pipelines between them
2. Maybe this happens because the module does not correctly manage several devices?

What about configuration of my pc:
GPUs: 2x 2060 SUPER
motherboard: TUF x299 MARK 2
CPU: i9 10900X
Power Supply: 1100W