jahboater wrote: ↑
Wed Dec 18, 2019 10:42 am
Could we say that at end of each benchmark run, the command "vcgencmd get_thottled" must return zero?
Then temperature, cooling, power supply issues are moot.
I recollect, possibly wrongly, that the 3B+ can throttle from 1400 to 1200 MHz without tripping the get_throttled flag. Is something similar possible with the 4B?
In a way, the most certain test whether the system goes into throttling is the measurement of known benchmark performance as a function of time. To be absolutely sure the work is getting done as fast as it should be, one may also need an external time source. Note that wrong assumptions about the way certain ARM processors report processor speeds have been discovered in recent times by such methods. In particular, if you are paying attention to performance, it becomes immediately obvious when a Linux driver says one thing but the processor is doing something else.
Back on topic, since source code is provided, it should be possible to reproduce the top performance results given here to determine whether your Pi is running correctly. Not only does such comparison check for throttling but it can also detect gradual degradation in performance (say with an SD card) correlated to subsequent failure.