We are now offering stressberry in the official repos. This is a tool for Raspberry Pis that will allow testing the core temperatures under different loads, collecting data on the run, and producing plots which can easily be compared.
Running it to collect data, including some optional switches:
-n to give the run a name
$this->bbcode_second_pass_code('', '% stressberry-run -n "2.0 GHz Naked" naked.dat')
Plotting the data, this example includes some optional switches:
-f to include a 2nd y-axis showing the frequency
--not-transparent to give a white background
-l 200 2000 to limit the frequency range on the 2nd y-axis from 200 MHz to 2,200 MHz
-t 20 90 to limit the temperature range from 20 to 90 degrees
$this->bbcode_second_pass_code('', '% stressberry-plot -o caseless.png -f -l 200 2200 -t 20 90 caseless.dat')
You can see by the orange line that the frequency was modulated once it hit the thermal limit of 85C.
You can also stack multiple runs on the same x-y plot like this:
-f -l 200 2200 is omitted here as frequency plots are not supported on stacked examples.
$this->bbcode_second_pass_code('', '% stressberry-plot -o combined.png -t 20 90 gempro.dat caseless.dat')