G.SKILL Ripjaws X Series 4GB 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-14900CL9S-4GBXL DDR3 1866 (PC3 14900), 240-Pin DDR3 SDRAM; Timing 9-10-9-28, Cas Latency 9, Voltage 1.5V Compatible with Intel LGA1150/LGA1155/LGA1156 and AMD APU/AM3+ platforms Intel XMP support for 1st, 2nd, 3rd and 4th Generation Intel Core Processors To reach rated memory speed, enabling Intel XMP profile or manual BIOS tuning is required