LOL good one!

Oh gosh, check out the https://litecoin.info/Mining_hardware_comparison wiki and follow that, then reduce your -I and try out different intensity settings until you get the best hash with the fewest invalids.  Another person here has collected settings, look back no more, I think, than 3-4 pages for one of his posts, or go to reddit, I think he posted there on the reddit drkcoin page