Samsung 4GB PC3-12800 DDR3-1600MHz non-ECC Unbuffered CL11 240-Pin DIMM M378B5273DH0-CK0 Memory Type DDR3 SDRAM Capacity 4GB Pins 240 Pin Bus Type PC-12800, Non-ECC Cycle Time 1.5ns Cas CL11 Data Transfer Rate 1600Mhz Memory Clock 200Mhz Rank Rank 2 Voltage 1.5