First off I have to Thank You!
I was having the same issue and you pointed me in the right direction.
I'm running Armbian 20.11.6 Buster off the SD Card on my 4GB RockPro64.
My system froze when starting CPU intensive tasks. For example trying to transcode a 4K Movie with Plex while using RDP to move files around.
However the MAX_SPEED value in /etc/default/cpufrequtils was 0.
So I guess it just tried to go as high as it could (or as high as the available values in /sys/devices/system/cpu/cpu{0,1,2,3}/cpufreq/scaling_available_frequencies based on this thread).
I now changed the MAX_SPEED value from 0 to 1512000 and I have not experienced crashes or freezes since then (only a few hours).
But now to my question.
According to the Rockchip RK3399 Datasheet (chapter 3.2, page 65) there are actually two different CPUs inside the RK3399. Cortex A53 (max 1.4 GHz) & Cortex A72 (max 1.8 GHz).
This is confirmed by running cpufreq-info which returns different "available frequency steps" for the CPUs 0-3 and 4-5.
By setting MAX_SPEED to 1512000 did I actually overclock the Cortex A53 and "underclock" the Cortex A72 aka prevent it from using its whole potential?
Does anybody or even you, ekkotron, know how I can set the maximum CPU frequency differently for the respective CPUs?
Or could I just change the values in /sys/devices/system/cpu/cpu{0,1,2,3}/cpufreq/scaling_available_frequencies according to the datasheet and set the MAX_SPEED in /etc/default/cpufrequtils back to 0 in order to prevent the CPU frequency from going to high?
I hope someone can give me some pointers. I'm fairly new to Linux so please correct me if I'm getting something wrong.
Thanks in advance! This forum helped me quite a bit so far.
