I always see it mentioned that you don't need to use both the 8 pin and the 6 pin power connector when mining.  But why not?  We are pushing these cards to their limit, why would that not help?  Is it because we are not overclocking the core, just the memory?  Or maybe because we're not actually driving monitors with the cards.

Has anyone tried using both power connectors to see if it does increase the hash rate?