I recently, went from 4g of ram to 8g and OC'd it to 1600. Resulted in a much bigger boost than I expected. I was able to increase my setting quite a bit. Settings that had been unplayable are now pretty smooth. OC'ing the rest of my rig didnt produce near the results.

Leads me to belive it really just needs to go on a diet, lol. I'm no expert tho, for sure.