Well depends on the game. But in most cases it is already very in favor of the AI, better weapons, more enemies, deadlier skills for enemies. For example the different versions of Fates, Birthright lets you grind exp and money, Conquest does not, so enjoy getting out of your way into peril for the precious side loot, while most likely behind levels.
So far I reached chapter 17 on Conquest/Lunatic getting all but one piece of side loot(which isn't worth it anyway) and without anyone dying a gruesome permadeath, but I see this chapter is going to be tough, so I'm sitting here with a piece of paper trying to impove my battle plan.
Get the jar opening kit!
Hey, mine has i3 and it runs them fine. Well I have an nvidia gts 450, so that's maybe something for 2011 tech.