Thanks for point that out, bakunin.
Coming from the Solaris world with ksh88 being a default ksh, I always make this mistake assuming the "minimalistic" ksh implementation.
Thanks again.
As an addendum to bakunin's post and I won't go into details...
Multi-CPUs and Multi-Core CPUs also have levels of cache both internal and external and controllers internal and external to suit because the contiguous RAM cannot be written to at the same time by multiple cores. The kernel takes care of most if not all of it. All of this adds heat to the system and it is not just the CPUs that faulter.
CPU/core loadings is/are a different matter so, which core is getting tested for loading or heating? Your test code does not determine that, made easier to read:
while : # While true...
do # do...
: # nothing, but I have no idea which core i am using... # (NOP)
done # and keep going, help I can't get out if something goes wrong...
And lastly how are you getting the temperature measurements from a/the builtin detector?
Do you have a separate detector per machine as backup and measuring that too?