I can see why benchmarking such a simple expression is trivial. I suppose there are several lessons learned here.

• Thanks to BrowserUk it is clear that in this particular situation the memory conservative:
  
  print "$_ : $h{ $_ }\n" for sort keys %h;
  
  is the best choice taking both efficiency and elegance into consideration.


• I learned how to benchmark my subroutines which will hopefully be of service as I learn to write more complex code


• And possibly most importantly I need to update my study materials!!!

Thanks again everybody!