6.12.6/6.12.10 - 11th Gen Intel QSV/VAAPI HW Transcode - Plex/Jellyfin/Tdarr - New CPU/iGPU behaviour

Issue:

Having Plex playback issues and unable to find cause. 

11th Gen Intel (11500) iGPU transcode have low transcoding speed and spike the CPU usage. 

Behaviour is identical on Plex, Jellyfin and Unmanic. Tdarr is not displaying this. 

Plex playback with transcode is constantly buffering with transcode speed at 0.1-0.6. This is with HW assisted encode/decode, direct stream audio and no subtitles. 

Enabled: HDR tone mapping/HW accel/HW accel encoding. Identical behaviour with HDR TM disabled.

Previously, transcoding the same files would utilize iGPU with low to no CPU impact. 

Used to be able to run +4 4K HDR transcodes with low system impact. Now it cannot even run one without non-stop buffering.

Uncertain when this started, it may have been even before 6.12.6. 

Any idea what a possible cause could be?

Test case:

Video transcode on Tdarr, Plex, Jellyfin, Unmanic (QSV/VAAPI).

Test results:

Tdarr: 100% iGPU, low CPU

Plex : +90% iGPU, high CPU

Jellyfin: 100% iGPU, high CPU

Unmanic +90% iGPU, high CPU

Tdarr:

Plex:

Versions:

CPU: Intel 11th gen 11500 - iGPU UHD 750

Unraid: 6.12.6, tried 6.12.10 (from 6.12.6 to 6.12.10) and ran into identical behaviour.

Plex: linuxserver - issue present on tested versions - 1.29/1.31/1.40.

Jellyfin: bbergle - latest

Tdarr: official - latest

Unmanic: josh5 - latest
 

Edited May 12, 20242 yr by ChrisRos