2 x 4GB (8GB Total) SK Hynix HMT451U6BFR8A-PB PC3L-12800U 1Rx8 Desktop Memory Memory Type: DDR3 SDRAM; Capacity: 4GB Pins: 240 Pin; Bus Type: PC-12800 Error Correction: Non-ECC; Cycle Time: 1.5ns Cas: CL11; Data Transfer Rate: 1600Mhz Memory Clock: 200Mhz; Rank: Rank 1; Voltage: 1.35