[FFmpeg-user] High CPU usage during scale_npp to low resolutions with multiple instances

[Dennis Mungai]

On Wed, 8 Apr 2020, 15:23 Valentin Schweitzer, <vs at nativewaves.com> wrote:

>
>
> Set this environment  variable: CUDA_DEVICE_MAX_CONNECTIONS=2
>
> Then retest and report back.
>
>
>
>
>
> One more thing: Could you show us the output of:
>
> numactl --hardware
>
> Thanks for your reply. We should have clarified that we are on Windows.
> Unfortunately, setting the environment variable CUDA_DEVICE_MAX_CONNECTIONS
> to 2 does not make a difference. The closest we got to a numactl equivalent
> on Windows is the NUMA view in the Task Manager which shows four NUMA nodes
> on our 24-core processor. Given this information, is it possible that
> either
> the Windows scheduler or the NVIDIA driver is having troubles with
> different
> ffmpeg instances being distributed to different NUMA nodes so that a lot of
> data has to be transferred between NUMA nodes, limiting the CPU? Are there
> any mitigations to this or is there anything else that we can analyze to
> clarify why different resolutions behave so differently on our machine?
>
> Greetings,
> Valentin
>


Hey there,

In your BIOS, disable the following options and retest:

1. SMT support (toggle to disabled).
2. X2APIC (toggle to disabled).

This will be the equivalent of setting "gaming mode" on the Ryzen consumer
processors. Apply these changes, retest and report back.

>