I have a Dell Inspiron 15r 5520. Here are the current specs: Core i7 @2.2 with turbo boost up to 3.2, 1TB 5400 RPM HDD, 8 GB DDR3 1600Mhz (I think), intel hm77 chipset, HD4000 graphics, Win 7 HP 64 Bit. What would be the best upgrade for $50 to boost my gaming performance?