I noticed that my HC2 was running slowly but didn't figure out why until I read this thread. Network performance was dismal too when measured with iperf3.
Where do I find these settings in the config tool? I only see the "Set CPU speed and governor (deprecated)".
In /etc/default/cpufrequtils I have
ENABLE=false
GOVERNOR="ondemand"
MAX_SPEED="0"
MIN_SPEED="0"
I put the following into /etc/apt/preferences.d/zfs in order to have apt prefer the Debian bookworm-backports ZFS packages to the armbian ones that are imported from Debian trixie (and currently not installable due to the t64 issue);
# Prefer Debian backports for zfs to armbian
Package: libnvpair3linux libuutil3linux libzfs4linux libzpool5linux zfs-dkms zfsutils-linux
Pin: release o=Debian Backports
Pin-Priority: 900