G.Skill 32GB DDR3-1333. Internal memory: 32768 MB, Internal memory type: DDR3, Memory clock speed: 1333 MHz. Memory voltage: 1.5 V. Compatibility: X79 Extreme4 X79 Extreme4-M X79 Extreme6 P9X79 DELUXE P9X79 WS P9X79 PRO GA-X79-UD3 GA-X79-UD5