Maybe cpu is at low energy mode ?
###### arm linux ######
➜ ~ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
performance
performance
performance
performance
➜ ~
Connection to 192.168.31.79 closed.
###### rk3399 Android ########
➜ Playground adb shell
* daemon not running; starting now at tcp:5037
* daemon started successfully
126|rk3399_all:/ $ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
interactive
interactive
interactive
interactive
interactive
interactive
rk3399_all:/ $
Do some warmup before benchmark.