I agree that if I had used system(), only with no redirection, the performance would probably be the same. I didn't try that, but I did try backticks WITH redirection and got a similar penalty (or loss of efficiency?) to using system() with redirection. I noted that in an update to the OP. I am sorry if I was unfair.

Tell me, is the following an accurate characterization:

By using backticks, I am effectively making the inside of my program the system call's STDOUT. Using backticks in a void context is the functional equivalent of redirecting output of the system call to /dev/null. With backticks, the computer has to do less work (and the programmer has to do less typing).

I don't mean to endorse of the practice by the above statements.