ado266 :
I have 8 GB DDR 3 1600 mhz im thinking about Buying 8 GB 2133 MHz
RAM should be bought as a matched kit, buying separately even if the same make and model id not guaranteed to work without problems. Even if it does work all the RAM will run at the slowest speed (1600Mhz). If you want to upgrade your RAM sell what you have and buy a 2x8Gb kit.