The raspberry pi has a command to determine whether the RPi has been "throttled" for what ever reason.
The output - in pure programmers methodology, is not user friendly.
So what does 0x0, 0x50005, 0x50000 exactly mean?
111100000000000001010 |||| ||||_ under-voltage |||| |||_ currently throttled |||| ||_ arm frequency capped |||| |_ soft temperature reached ||||_ under-voltage has occurred since last reboot |||_ throttling has occurred since last reboot ||_ arm frequency capped has occurred since last reboot |_ soft temperature reached since last reboot
For a better understanding. See harlemsquirrel.
NOTE: The script is slightly out of date as bits 3 and 19 have now been added since the page was published. Here
0x0 means nothing wrong
0x50000 means throttled has occurred since the last reboot.
0x50005 means you are currently under-voltage and throttled.