Hallo,
I download the 6.12.6 kernel, use all vanilla patches until 6.12.14 and use debian bookworm on this old devices ..
While network speed via iperf3 measures are ok (90 MBytes/sec) the HDD speed (/dev/sda) is really worse !!
I got about 15-22 MByte/sec by doing dd if=/dev/sda of=/dev/null bs=1024k status=progress ...
I got two devices, and if I go back to 5.15.121 (also from here) I got about 120-135 MByte / sec (2 TB HDD)
with the above dd command ...
Any suggestions about this very large change ??