synology docker Jellyfin very slow and high iowait when FFmpeg Transcode

[allen]

Hi, there! I deployed Jellyfin using Docker on my Synology NAS and enabled hardware acceleration. However, when I start playing a video, my Synology becomes extremely slow and the system experiences very severe iowait. Can anyone help me look into this? Here are some system info and logs.

Synology:

• Model name DS224+
  
• CPU INTEL Celeron J4125
  
• CPU Clock rate 2 GHz
  
• Total physical memory 2048 MB
  

FFmpeg log:


/usr/lib/jellyfin-ffmpeg/ffmpeg -analyzeduration 200M -probesize 1G -f matroska -init_hw_device vaapi=va:/dev/dri/renderD128,driver=iHD -init_hw_device qsv=qs@va -filter_hw_device qs -canvas_size 1920x1080 -i file:"/video2/xxxx.UHD.BluRay.2160p.HDR.TrueHD.Atmos7.1.5.Audio.x265.10bit-DreamHD/xxx.UHD.BluRay.2160p.HDR.TrueHD.Atmos7.1.5.Audio.x265.10bit-DreamHD.mkv" -map_metadata -1 -map_chapters -1 -threads 0 -map 0:0 -map 0:1 -map -0:0 -codec:v:0 h264_qsv -preset veryfast -mbbrc 1 -b:v 33385810 -maxrate 33385811 -rc_init_occupancy 66771620 -bufsize 133543240 -profile:v:0 high -level 51 -g:v:0 72 -keyint_min:v:0 72 -filter_complex "[0:6]scale,scale=3840:2160:fast_bilinear[sub];[0:0]setparams=color_primaries=bt709:color_trc=bt709:colorspace=bt709,scale=trunc(min(max(iw\,ih*a)\,min(3840\,2160*a))/2)*2:trunc(min(max(iw/a\,ih)\,min(3840/a\,2160))/2)*2,format=yuv420p[main];[main][sub]overlay=eof_action=pass:repeatlast=0" -start_at_zero -codec:a:0 libfdk_aac -ac 2 -ab 256000 -af "volume=2" -copyts -avoid_negative_ts disabled -max_muxing_queue_size 2048 -f hls -max_delay 5000000 -hls_time 3 -hls_segment_type fmp4 -hls_fmp4_init_filename "f156cdfa9cdbd2c25287b9473e82ad8a-1.mp4" -start_number 0 -hls_segment_filename "/cache/transcodes/f156cdfa9cdbd2c25287b9473e82ad8a%d.mp4" -hls_playlist_type vod -hls_list_size 0 -hls_segment_options movflags=+frag_discont -y "/cache/transcodes/f156cdfa9cdbd2c25287b9473e82ad8a.m3u8"

ffmpeg version 7.1.2-Jellyfin Copyright © 2000-2025 the FFmpeg developers
  built with gcc 14 (Debian 14.2.0-19)
  configuration: --prefix=/usr/lib/jellyfin-ffmpeg --target-os=linux --extra-version=Jellyfin --disable-doc --disable-ffplay --disable-static --disable-libxcb --disable-sdl2 --disable-xlib --enable-lto=auto --enable-gpl --enable-version3 --enable-shared --enable-gmp --enable-gnutls --enable-chromaprint --enable-opencl --enable-libdrm --enable-libxml2 --enable-libass --enable-libfreetype --enable-libfribidi --enable-libfontconfig --enable-libharfbuzz --enable-libbluray --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libopenmpt --enable-libdav1d --enable-libsvtav1 --enable-libwebp --enable-libvpx --enable-libx264 --enable-libx265 --enable-libzvbi --enable-libzimg --enable-libfdk-aac --arch=amd64 --enable-libshaderc --enable-libplacebo --enable-vulkan --enable-vaapi --enable-amf --enable-libvpl --enable-ffnvcodec --enable-cuda --enable-cuda-llvm --enable-cuvid --enable-nvdec --enable-nvenc
  libavutil      59. 39.100 / 59. 39.100
  libavcodec    61. 19.101 / 61. 19.101
  libavformat    61.  7.100 / 61.  7.100
  libavdevice    61.  3.100 / 61.  3.100
  libavfilter    10.  4.100 / 10.  4.100
  libswscale      8.  3.100 /  8.  3.100
  libswresample  5.  3.100 /  5.  3.100
  libpostproc    58.  3.100 / 58.  3.100
libva info: VA-API version 1.22.0
libva info: Trying to open /usr/lib/jellyfin-ffmpeg/lib/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_22
libva info: va_openDriver() returns 0


Metadata:
    encoder        : libebml v1.3.6 + libmatroska v1.4.9
    creation_time  : 2019-11-05T07:54:17.000000Z
  Duration: 01:34:40.72, start: 0.000000, bitrate: 33385 kb/s
  Chapters:

[hls @ 0x7fa2606c7580] Opening '/cache/transcodes/bd57a9652f27716f4f6f9ae4acc42b87-1.mp4' for writing
Output #0, hls, to '/cache/transcodes/bd57a9652f27716f4f6f9ae4acc42b87.m3u8':
  Metadata:
    encoder        : Lavf61.7.100
  Stream #0:0: Video: h264, nv12(tv, bt709, progressive), 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 33385 kb/s, 23.97 fps, 26201 tbn
      Metadata:
        encoder        : Lavc61.19.101 h264_qsv
      Side data:
        Mastering Display Metadata, has_primaries:1 has_luminance:1 r(0.6800,0.3200) g(0.2650,0.6900) b(0.1500 0.0600) wp(0.3127, 0.3290) min_luminance=0.000000, max_luminance=1000.000000
        Content Light Level Metadata, MaxCLL=0, MaxFALL=0
        cpb: bitrate max/min/avg: 33385811/0/33385810 buffer size: 133543240 vbv_delay: N/A
  Stream #0:1: Audio: aac, 48000 Hz, stereo, s16, 256 kb/s (default)
      Metadata:
        encoder        : Lavc61.19.101 libfdk_aac
      Side data:
        cpb: bitrate max/min/avg: 256000/256000/256000 buffer size: 0 vbv_delay: N/A
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    0 fps=0.0 q=0.0 size=N/A time=N/A bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    1 fps=0.0 q=12.0 size=N/A time=-00:00:00.08 bitrate=N/A speed=N/A   
frame=    2 fps=0.0 q=26.0 size=N/A time=-00:00:00.04 bitrate=N/A speed=N/A   
frame=    2 fps=0.0 q=26.0 size=N/A time=-00:00:00.04 bitrate=N/A speed=N/A   
frame=    2 fps=0.0 q=26.0 size=N/A time=-00:00:00.04 bitrate=N/A speed=N/A   
frame=    4 fps=0.1 q=26.0 size=N/A time=00:00:00.00 bitrate=N/A speed=  0x   
frame=    4 fps=0.1 q=26.0 size=N/A time=00:00:00.00 bitrate=N/A speed=  0x   
frame=    5 fps=0.1 q=26.0 size=N/A time=00:00:00.04 bitrate=N/A speed=0.000579x   
frame=    5 fps=0.1 q=26.0 size=N/A time=00:00:00.04 bitrate=N/A speed=0.000575x   
frame=    5 fps=0.1 q=26.0 size=N/A time=00:00:00.04 bitrate=N/A speed=0.000571x   
frame=    6 fps=0.1 q=26.0 size=N/A time=00:00:00.08 bitrate=N/A speed=0.00113x   
frame=    7 fps=0.1 q=26.0 size=N/A time=00:00:00.12 bitrate=N/A speed=0.00169x   
frame=    8 fps=0.1 q=26.0 size=N/A time=00:00:00.16 bitrate=N/A speed=0.00224x   
frame=    8 fps=0.1 q=26.0 size=N/A time=00:00:00.16 bitrate=N/A speed=0.00222x   
frame=    8 fps=0.1 q=26.0 size=N/A time=00:00:00.16 bitrate=N/A speed=0.00221x   
frame=    8 fps=0.1 q=26.0 size=N/A time=00:00:00.16 bitrate=N/A speed=0.00219x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00272x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00271x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00269x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00267x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00265x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00264x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00262x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.0026x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00259x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00257x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00256x   
frame=    9 fps=0.1 q=26.0 size=N/A time=00:00:00.20 bitrate=N/A speed=0.00254x 



Jellyfin & Docker Configuration：

version: '3.8'
services:
  jellyfin:
    image: jellyfin/jellyfin:2025112405
    container_name: jellyfin
    restart: unless-stopped
    ports:
      - "8096:8096"
    volumes:
        - /volume1/video:/video
        - /volume1/docker/jellyfin/cache:/cache
        - /volume1/docker/jellyfin/config:/config
        - /volume1/downloads/complete:/video2
    environment:
      - UID=0
      - GID=0
      - GIDLIST=0
    devices:
      - /dev/dri/renderD128:/dev/dri/renderD128
      - /dev/dri/card0:/dev/dri/card0
    user:937

   
   
   
   
   

[pxr5]

Have a look here and see what your GPU (Gemini Lake from 2019) can handle https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video. Straight away you have AV1 decoding enabled which your CPU/GPU can't handle. Synology NAS are not the best for HW decoding. Even your newer NAS will struggle with 4K, but set up as per the link and see what works. And why disable HEVC?