ebin-dev

These timeout issues are actually linux kernel related (see i.e. here).
To get rid of those issues, disable scatter/gather offloading (just execute 'ethtool -K <iface> sg off' ; replace <iface> by your interface name like eth0). But transmission speed will suffer !
 
With some optimizations the timeout issues also disappear. Dealing with 2.5G traffic is quite a burden on the CPUs! Use jumbo frames.
 
I am using the following content in /etc/rc.local to bind the tasks involved to the big cores (sata (cpu 4) and 2.5g network traffic (cpu 5)).
 
How is your PC connected to your Helios64 ? If you are using an 2.5G USB-C adapter it should contain the latest version of the rtl8156 chip (31.04) (i.e. like this one).
 
#!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. cd /sys/devices/system/cpu/cpufreq for cpufreqpolicy in 0 4 ; do echo 1 > policy${cpufreqpolicy}/ondemand/io_is_busy echo 25 > policy${cpufreqpolicy}/ondemand/up_threshold echo 10 > policy${cpufreqpolicy}/ondemand/sampling_down_factor echo $(cat policy${cpufreqpolicy}/cpuinfo_transition_latency) > policy${cpufreqpolicy}/ondemand/sampling_rate done for i in $(awk -F":" "/ahci/ {print \$1}" < /proc/interrupts | sed 's/\ //g'); do echo 10 > /proc/irq/$i/smp_affinity done for i in $(awk -F":" "/xhci/ {print \$1}" < /proc/interrupts | sed 's/\ //g'); do echo 20 > /proc/irq/$i/smp_affinity done exit 0  
rk3399-kobol-helios64.dtb-6.10.2-L2-hs400-opp rk3399-kobol-helios64.dtb-6.6.34-L2-hs400-opp

Download a new system image with linux 6.6.y, flash it to another sd card (just use etcher) and boot from it.
I would recommend to copy the dtb from my post (for the 6.6 branch) and execute 'update-initramfs -u'.
If you are using the 2.5G interface, replace the rtl firmware in /lib/firmware/rtl_nic. No need to install a new r8152 driver.
 
You can then copy the system from sd to emmc using armbian-config (this also changes the bootloader on emmc) and boot from emmc.
(If there are issues with the new  bootloader installed on emmc, flash the following u-boot to emmc (linux-u-boot-edge-helios64_22.02.1_arm64) (see here).)
 

MAC address changed in edge kernels to native hardware address (see here).

To install the latest kernel 6.6.69 just load the three files (image, dtb, headers) into a single folder, and execute 'dpkg -i linux*' inside that folder and reboot.

There are new Armbian 24.05 images available on the Helios64 download page: both images Bookworm minimal and Jammy Desktop are based on linux 6.6.30 (download them !).
 
Again, the rtl_nic firmware (in /lib/firmware/rtl_nic) should be replaced by the version downloaded from git.kernel.org, such that the 2.5G LAN interface works correctly.
 
I would also recommend to copy the dtb attached below to /boot/dtb/rockchip/rk3399-kobol-helios64.dtb (execute 'update-initramfs -u' after that). It includes the 75mV bump of the opp states for the fast cores as suggested by @prahal, it enables the L2 cache info and it enables hs400 speed on emmc again. In particular the 75mV bump has a very positive effect on stability.
 
The bootloader that comes with it would appear to contain the Rockchip DDR blob. It should be fine. If you have an issue with u-boot, just flash linux-u-boot-edge-helios64_22.02.1_arm64 as recommended before.
 
The cpufreq ondemand governor is still the best choice. Good settings are
# cat /etc/default/cpufrequtils ENABLE=true MIN_SPEED=600000 MAX_SPEED=1800000 GOVERNOR=ondemand  
Enjoy.
 
P.S.: If you like a system more responsive to server tasks or push the 2.5G interface to the limits, some fine tuning is helpful.
 
rk3399-kobol-helios64.dtb-6.6.30-L2-hs400-opp

@buhtux For the mainline r8152 driver you need to copy the rtl_nic firmware files into /lib/firmware/rtl_nic (see also here).