Nightly pi5 high cpu usage on 4k

    Hi.

    Im not quite sure if it is a bug, or if some settings in some file got changed so i ask first before try to create logs.

    I noticed that with the builds which got released after 20250719-47e72e0 (not sure which as the next one i tried was 20250725-f0482de where i noticed it) the playback of 4k files is choppy as the cpu usage seems to be loaded at around 90-100%, while on the build from the 19 and prior the files get played fluid with only around 20-40% cpu usage.


    I did not change anything on the settings


    Log from the build where stuff runs fine: https://paste.libreelec.tv/enough-anemone.log

    Log from current build (20250731-ee7a2e6.img.gz) : https://paste.libreelec.tv/settling-pipefish.log


    If only stuff on the settings changed, where would I need to change it that it runs OK on those files again?

    Quote from popcornmix

    I'm not aware of any regression.

    If you could identify the exact nightly build where the performance regression started, then the changes there can be investigated.

    Edit: We are suspecting https://github.com/LibreELEC/LibreELEC.tv/pull/10258

    If it is still needed i can try out the 4 builds between those i saw that happening, but most likely wont be able today, and more over the weekend


    Quote from chewitt

    The (bad) log shows two videos, one HEVC, one H264. To confirm, the video is choppy with both videos?

    As far as i noticed, it is only on the second one, i assume it is the h264 one. (did make pictures, and the first has almost no change in cpu usage)

    Not sure as i not tested that, but i think the 1080p videos all ran fine (used the 25th build 1-2

    days before i encountered the issue).

    small correction to the above post: SDRAM_BANKLOW=3 needs to go into the bootloader / rpi-eeprom config, not into config.txt.

    Run rpi-eeprom-config -e and add SDRAM_BANKLOW=3 to the end of the file, then reboot.

    With this change a 4k H264 file played fine on my RPi5.

    BTW: no need to test older builds.

    so long,

    Hias