That seems to be the prevailing wisdom, but in ten years, I have yet to meet a programmer who was 5 to 6 times as productive as I am. Also, I assume I must be average, because I'm certainly not 5 or 6 times as productive as my co-workers. Maybe twice as productive, a bit more during those wonderful, 24 hour frenzies.

Just out of curiosity, where do you know these programmers, and what is used for productivity metrics?