G.SKILL 8GB (2 x 4GB) Ripjaws X Series DDR3 1333MHz (PC3-10666) 240-Pin. Desktop Memory F3-10666CL9D-8GBXL 8GB 4GBx2 Dual Channel Kit Ripjaws X Series DDR3 1333 (PC3 10666) CL 9-9-9-24 Voltage:1.5V F3-10666CL9D-8GBXL