L.S. After installing Armbian_20.02.1_Rock64_buster_current_188.8.131.52z on my 4GB rock64 running on SD card - I could run for days 2 processes with "openssl speed" resulting in 2 CPU's 100% busy. - But when I added a third "openssl speed" it only takes minutes to freeze the board. - Further the "ondemand" scaling_governor is active (default setting) I noticed that distributed /etc/default/cpufrequtils contains line: ==> MAX_SPEED=1390000 This value is not in the list with valid values for this CPU : ==> 408000 600000 816000 1008000 1200000 1296000 1512000 After updating this to valid value and restart service cpufrequtils: ==> sed -i "s/MAX_SPEED=.*/MAX_SPEED=1296000/" /etc/default/cpufrequtils service cpufrequtils restart The rock64 is now already a few hours running happily 100% CPU on all 4 its core's at appr 80C. It even runs happy now with 4 CPU's 100% with MAX_SPEED=1512000 for nearly an hour, throttling down to 1.3 or 1.2GHz at appr 84C - Can this be reproduced by some one else using the default distribution with 4x100% CPU usage? - Can it be that I have an old level rock64 board (I bought it appr 2 years back) that is causing this issue? - Is it possible that the CPU / kernel freezes because of an incorrect MAX_SPEED value? ref: Linux rock64 5.4.27-rockchip64 #20.02.6 SMP PREEMPT Tue Mar 24 23:43:02 CET 2020 aarch64 GNU/Linux regards Eric Experimenting with armbian in these worrying times.