G.Skill F3-10666CL7D-4GBRH  Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333MHz (PC3 10666) Desktop Memory 240-Pin DDR3 1333MHz (PC3 10666) Dual Channel Kit, Unbuffered, Non-ECC Tested Latency: 7-7-7-21-2N, Tested Voltage: 1.50v, 4GB (2 x 2GB), Intel XMP (Extreme Memory Profile) Ready