OCZ PC3-12800 Obsidian 4 GB Dual Channel Kit OCZ3OB1600LV4GK 1600MHz DDR3/Obsidian Black XTC Heatspreader CL 9-9-9-24 (CAS-TRCD-TRP-TRAS) Available 6GB Triple Channel Kits/1.65 Volts Core i7 Ready/240 Pin DIMM Unbuffered