RickH...
I don't remember where exactly I read it, but it was not from Asus. I believe it was on another forum, the poster claimed to have one of those PCI cards that will read back the bus speed.(PC Guiger) I'm simply taking that and running with it, as it's the only info I've found anywhere as to what the Turbo settings really do. Perhaps I should have stated this before, as I don't mean to mislead anyone, but this does seem to be the common consensus as to what the Turbo settings do.
I have emailed Asus Tech Support asking for info on this matter, but have never recieved a reply.