Results: Battlefield 3 And Skyrim
The performance variations in Battlefield 3 are too small to attribute to configuration differences. So far, it looks like cheap DDR3-1600 is a bargain.
The Elder Scrolls V: Skyrim benefits from faster or quicker RAM, but those benefits decrease as resolution is increased and graphics load goes up.
Although in reality 1600 can do the job just fine and it could overclock nicely too if you get the right RAM.